Reading characters from a string and assigning them to a single char???

Hi there,

I'm having a bit of a mare.

I am attempting to convert ROMAN NUMERALS into ARABIC NUMBERS...

I cannot for the life of me seem to be able to read a character from a string...

I have been trying to write a 'SORT' function that uses a switch to sort through and count the different letters in a string that has been input either via the keyboard or from a file stream...

Here is my full programme so far... any hints as to how I could read the letters would be a godsend... I have been doing this for about 20 huors straight and still can't get it!

Code:

---

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

char LETTERS[16];
int index;
int REP;
int fork;
int countM, countD, countC,  countL,  countX,  countV,  countI;
int        countCM, countCD, countXC, countXL, countIX, countIV;

int valueM; int valueD; int valueC ; int valueL; int valueX;
int valueV; int valueI; int valueCM; int valueCD; int valueXC;
int valueXL; int valueIX; int valueIV;

void READFILE ();
void READKEYBOARD ();
void SORT (char[]);
void RESTART ();
void COUNT (int);
void COUNTLESS (int);
void COUNTER (char []);
void READLETTER2 (char[]);
int TOTAL (int, int, int, int, int, int, int, int, int, int, int, int, int);


int TOTAL (int m, int d, int c, int l, int x, int v, int i, int cm, int cd, int xc, int xl, int ix, int iv)  // TOTALS UP THE VALUES OF THE NUMERALS
{
        return (m+d+c+l+x+v+i+cm+cd+xc+xl+ix+iv);
}

void COUNTER (char counter[16])  // TALLIES AND ERROR CHECKS THE DOUBLE NUMERAL COUNTS
{       
        switch (counter[index])
        {
        case '\0':
                break;
        case 'D':
                REP = 1; COUNTLESS(countC); COUNT(countCM); break;
        case 'M':
                REP = 1; COUNTLESS(countC); COUNT(countCD); break;
        case 'C':
                REP = 1; COUNTLESS(countX); COUNT(countXC); break;       
        case 'L':
                REP = 1; COUNTLESS(countX); COUNT(countXL); break;
        case 'X':
                REP = 1; COUNTLESS(countI); COUNT(countIX); break;
        case 'V':
                REP = 1; COUNTLESS(countI); COUNT(countIV); break;
        default:
                printf("You have input an invalid character");
                RESTART ();
        }
}

void COUNTLESS (int countless)                        // CHECKS AND TALLIES THE SINGLE NUMERAL COUNTS
{
        (countless --);
}

void RESTART ()                        // RESTARTS THE WHOLE PROGRAMME
{
        int yn;
        printf("Do you wish to try again? Enter Y to continue \n(else enter anything else to quit): ");
        scanf("%i", &yn);

        if ((yn = 'Y')|| (yn = 'y'))
                printf("Please quit and restart the programme");
        else
        exit(0);
}

void SORT (char UNKNOWN[])                // DETERMINES WHICH NUMERALS HAVE BEEN ENTERED FROM THE STRING AND PERFORMS FUNCTION "COUNT" ON THEM
{
        switch (UNKNOWN[index])
        {
        case 'M':
                REP = 4; COUNT(countM); break;
        case 'D':
                REP = 1; COUNT(countD); break;
        case 'C':
                REP = 3; COUNT(countC); READLETTER2(LETTERS); break;
        case 'L':
                REP = 1; COUNT(countL);        break;       
        case 'X':
                REP = 3; COUNT(countX); READLETTER2(LETTERS); break;
        case 'V':
                REP = 1; COUNT(countV); break;
        case 'I':
                REP = 3; COUNT(countI); READLETTER2(LETTERS); break;
        default:
                        printf("You have input an invalid character"); RESTART ();
        }
}
       
void READLETTER2 (char UNKNOWN[])                // READS THE SECOND THE SECOND NUMERAL AFTER THE PRIMARIES C, X and I AND PERFORMS TALL
{       
        index ++;       
        COUNTER (LETTERS);
}

void COUNT (int count)                        // CHECKS AND TALLIES THE SINGLE NUMERAL COUNTS
{
        (count ++);
        if (count > REP)
        {
                printf("You have input too many consecutive numerals");
                RESTART();
        }
}

void READKEYBOARD ()                        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
{                                                                        //get the user to input a ROMAN NUMERAL SEQUENCE
        char Tab[16];                                               
        printf("\n Please input your ROMAN NUMERALS from the keyboard (in CAPS only): ");
        scanf("%s", &Tab);
        strcpy(LETTERS, Tab);
}

void main ()
{                                                                                // DECLARE VARIABLES ETC...
        int ANSWER;       
        int c=0;
        int countM = 0; int countD = 0; int countC = 0; int countL = 0; int countX = 0; int countV = 0; int countI = 0;
        int        countCM = 0; int countCD = 0; int countXC = 0; int countXL = 0; int countIX = 0; int countIV = 0;
       
        // CHOOSE BETWEEN KEYBOARD & BATCH MODE

        do
        {
                printf("\n Choose 1 for FILE input");
                printf("\n Choose 2 for KEYBOARD input: ");
                scanf("%i", &c);
        }       
        while ((c <=0) || (c >=3));       
       
        if (c == 1)
                printf("You have chosen one - file input");

        else if (c == 2)
        {
                printf("You have chosen two - file input");        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
                READKEYBOARD ();
        }
       
        for (index = 0; LETTERS[index] != '\0'; index++);
        SORT (LETTERS);

        index = -1;

        int valueM = 1000*countM; int valueD = 500*countD; int valueC = 100*countC; int valueL = 50*countL; int valueX = 10*countX;
        int valueV = 5*countV; int valueI = 1*countI; int valueCM = 900*countCM; int valueCD = 400*countCD; int valueXC = 90*countXC;
        int valueXL = 40*countXL; int valueIX = 9*countIX; int valueIV = 1*countIV;
       
        ANSWER = TOTAL(valueM, valueD,  valueC,  valueL,  valueX, valueV, valueI, valueCM,  valueCD, valueXC,  valueXL,  valueIX,  valueIV);

        printf("The value you input in ROMAN NUMERALS was: %s", LETTERS);
        printf("The equivalent value in Arabic numbers is: %i", ANSWER);

}

---

Your program looks like C, but this is the C++ forum. Next time use the C forum.

Code:

---

void COUNTLESS (int countless)                        // CHECKS AND TALLIES THE SINGLE NUMERAL COUNTS
{
        (countless --);
}

---

That function isn't going to affect the value of its parameter from the calling function. That is:

Code:

---

x = 3;
COUNTLESS(x);
// x is still 3

---

If you want the changes to be reflected, declare the parameter to be a reference or a pointer.

On the other hand, why do you need a function for such a simple operation?

Same comments for COUNT().

main() returns int, not void. See the FAQ.

Code:

---

        char Tab[16];                                               
        printf("\n Please input your ROMAN NUMERALS from the keyboard (in CAPS only): ");
        scanf("%s", &Tab);
        strcpy(LETTERS, Tab);

---

Drop that &. And why not read directly into LETTERS?

You can remove the "in CAPS only" restriction by using toupper() from <ctype.h> on each character in the string.

Code:

---

        if ((yn = 'Y')|| (yn = 'y'))
                printf("Please quit and restart the programme");

---

Use == for comparison, not =, which is for assignment. Also, tolower() or toupper() would make you job easier.

Code:

---

if(tolower(yn) == 'y')

---

In TOTAL() you have this:

Code:

---

return (m+d+c+l+x+v+i+cm+cd+xc+xl+ix+iv);

---

Perhaps you want something like this?

Code:

---

return (i) + (v*5) + (x*10) + (l*50) + /* ... */;

---

Code:

---

        printf("The value you input in ROMAN NUMERALS was: %s", LETTERS);
        printf("The equivalent value in Arabic numbers is: %i", ANSWER);

---

Consider printing some newlines (\n) there.

BTW, in C++, standard practice is to use lowercase for variable and function names, or sometimes initial capitals (aVariable, TheClass) -- but not all capitals. That's usually reserved for constants. Your way is fine, but initially readers might be a little confused.

Oooookay. Some comments:
(1) int main [with a return 0; at the end], instead of void main
(2) all those global variables, some of which get hidden by identically named variables in main. So, for instance, the countM that SORT sees is not the same countM that main sees.
(3) All these CAPITALIZED names; why?
(4) COUNT and COUNTLESS do not change their parameters (a local copy is changed, but that is not returned), so none of the countLetter variables ever change.
(5) Your readahead doesn't check the current character; CC, XC, and IC all have the same effect (take away an X (even if one doesn't exist!) and add an XC -- or it would, if COUNT and COUNTLESS were working).
(6) You should set up a loop so that if RESTART returns true (say), then the loop continues, else it stops and you finish off in main.
(7) I think you've got the "reading characters from a string and assigning them to a single char" bit down perfectly (except for index being a global variable).

I suggest taking away the global variables and passing things in and returning them properly. If a value needs to be changed (such as in COUNT) return it. Pass index into the SORT and READLETTER2 functions, or better yet, just pass the string into SORT and let SORT do the loop.

Many thanks for both your suggestions... I shall use them wisely - you have been extremely helpful...

Hello again,

I have had a go at piecing this back together into a more orderly structure and have learnt a few things from your advice...

I am just a little bit confused about how to use these counts properly. I thought if I used them as a global variable it would work but aren't there too many of them to keep passing through functions and how would I go about doing that. I can't see how it would be done. I think I have corrected the index... passing? I mean to pass the counts between 'sort' 'readletter' and 'counter' functions... seems impossible to my small brain.

Any advice would be taken humbly...
Thanks

Code:

---


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

char LETTERS[16];


int total (int, int, int, int, int, int, int, int, int, int, int, int, int);
int countless (int);
int counter (char, int);
int readletter2 (char, int);
int count (int, int);
void sort (char);                                // converts the NUMERALS into counts
void readkeyboard ();                                        // reads the string from the keyboard
void ask ()        ;                                        // asks for input type
int fork(int);                                                // choose (F)ile or (K)eyboard



int total (int m, int d, int c, int l, int x, int v, int i, int cm, int cd, int xc, int xl, int ix, int iv)
{
        return (m*1000) + (d*500) + (c*100) + (1*50) + (x*10) + (v*5) + (i) + (cm*900) + (cd*400) + (xc*90) + (xl*40) + (ix*9) + (iv*4);
}


int countless (int a)
{
        a --;
        return a;
}

int counter (char Tab[16], int i)  // TALLIES AND ERROR CHECKS THE DOUBLE NUMERAL COUNTS
{       
        switch (Tab[i])
        {
        case '\0':
                break;
        case 'D':
                REP = 1; countless(countC); count(countCM, REP); break;
        case 'M':
                REP = 1; countless(countC); count(countCD, REP); break;
        case 'C':
                REP = 1; countless(countX); count(countXC, REP); break;       
        case 'L':
                REP = 1; countless(countX); count(countXL, REP); break;
        case 'X':
                REP = 1; countless(countI); count(countIX, REP); break;
        case 'V':
                REP = 1; countless(countI); count(countIV, REP); break;
        default:
                printf("You have input an invalid character");
                RESTART ();
        }
        return i;
}


int readletter2 (char Tab[16], int i)                // READS THE SECOND THE SECOND NUMERAL AFTER THE PRIMARIES C, X and I AND PERFORMS TALL
{       
        i ++;       
        counter (Tab[16], int i);
        return i;
}



int count (int i, int rep)                        // CHECKS AND TALLIES THE SINGLE NUMERAL COUNTS
{
        (i ++);
        if (i > rep)
        {
                printf("You have input too many consecutive numerals");
                RESTART();
        }
        return i;
}


char sort (char Tab[16])
{
        int i;
        int REP;

        for (i = 0; Tab[i] != '\0'; i++);

                {       
                        switch (Tab[i])
                        {
                                case 'M':
                                        REP = 4; count(countM, REP); break;
                                case 'D':
                                        REP = 1; count(countD, REP); break;
                                case 'C':
                                        REP = 3; count(countC, REP); readletter2(Tab[i], i); break;
                                case 'L':
                                        REP = 1; count(countL, REP); break;
                                case 'X':
                                        REP = 3; count(countX, REP); readletter2(Tab[i], i); break;
                                case 'V':
                                        REP = 1; count(countV, REP); break;
                                case 'I':
                                        REP = 3; count(countI, REP); readletter2(Tab[i], i); break;
                                default:
                                        printf("You have input an invalid character"); RESTART ();
                        }
                }
}


void readkeyboard (char Tab[16])                        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
{                                                                        //and change string to upper case       
        int x;

        printf("\n Please input your ROMAN NUMERALS from the keyboard: ");
        scanf("%s", LETTERS);
        for (x=0; x<strlen(LETTERS); ++x)
        {
                LETTERS[x] = toupper(LETTERS[x]);
        }
}


void ask ()
{
        printf("\n Choose 1 for FILE input");
        printf("\n Choose 2 for KEYBOARD input: ");
}       

int fork(int c)
{
        scanf("%i", &c)       
               
                while ((c <=0) || (c >=3));       
       
        if (c == 1)
                printf("You have chosen one - file input");
        else if (c == 2)
        {
                printf("You have chosen two - file input");        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
                readkeyboard ();
        }

int main ()
{                        // DECLARE VARIABLES ETC...

        int countM = countD = countC = countL = countX = countV = countI = countCM = countCD = countXC = countXL = countIX = countIV = 0;
        int answer = 0;

        // CHOOSE BETWEEN KEYBOARD & BATCH MODE

        ask();
        fork ();
        sort (LETTERS);
        answer = total(countM, countD, countC, countL, countX, countV, countI, countCM, countCD, countXC, countXL, countIX, countIV);

        printf("The value you input in ROMAN NUMERALS was: %s", LETTERS);
        printf("The equivalent value in Arabic numbers is: %i", answer);
}

---

Code:

---

counter (Tab[16], int i);

---

When you pass variables to functions, you don't include types, and in this case, to pass an array, you use just the array's name without any square brackets. Using "Tab[16]" means that you're passing the 17th element in Tab to the function -- which, as well as being one character instead of an entire array, is also one past the end of the array.

In other words, you probably want something like

Code:

---

counter(Tab, i);

---

Code:

---

int fork(int c)
{
        scanf("%i", &c)       
               
                while ((c <=0) || (c >=3));

---

Since that while loop doesn't have a matching do, it's an ordinary while and not a do-while loop. This means that if c <= 0 or c >= 3, the while loop will enter an infinite loop, because

Code:

---

while ((c <=0) || (c >=3));

---

is the same as

Code:

---

while ((c <=0) || (c >=3)) {

}

---

I think you meant to use

Code:

---

int fork(int c)
{
        do

        scanf("%i", &c)       
               
                while ((c <=0) || (c >=3));

---

or, more readably,

Code:

---

int fork(int c)
{
        do {
                scanf("%i", &c)       
        } while ((c <=0) || (c >=3));

---

BTW, fork() is the same of a standard POSIX function, so consider a different name for your function.

Code:

---

        for (x=0; x<strlen(LETTERS); ++x)
        {
                LETTERS[x] = toupper(LETTERS[x]);
        }

---

strlen() is expensive in terms of time to compute, so if you save its value your code will be much more efficient:

Code:

---

        int len = strlen(LETTERS);
        for (x=0; x<len; ++x)
        {
                LETTERS[x] = toupper(LETTERS[x]);
        }

---

(I like to use variables of type size_t to store the return value of strlen() and loops that depend on this value, but int should be sufficient in most cases.)

Code:

---

(i ++);

---

Those parentheses are unnecessary, but they don't do any harm.

Code:

---

int countM = countD = countC = countL = countX = countV = countI\
= countCM = countCD = countXC = countXL = countIX = countIV = 0;

---

You cannot do that when you're declaring variables. You can do it after the variables are declared, but not there. In addition, several other functions use these variables (which are local to main()) -- in order for this to work, you'll need to declare these variables as global (bad idea), or pass them on to those functions that need them, such as sort() (semi-okay idea). Best of all, because there are so many variables, you might want to do something like this.

Code:

---

#define COUNT_M 0
#define COUNT_D 1
#define COUNT_C 2
/* ... */

int count[13];

---

or, perhaps

Code:

---

enum {
    COUNT_M
    COUNT_D
    COUNT_C,
    /* ... */
};

int count[13];

---

which is the same thing, except the compiler does the counting for you; and then you'd use

Code:

---

count[COUNT_C]

---

instead of countC. Or something like that. Imagine what the declaration of total() would look like then!

Code:

---

int total(int count[13]) {

---

So simple . . . .

Code:

---

int fork(int c)
{
        scanf("%i", &c)

---

Why are you clobbering a parameter like that? I think this would do:

Code:

---

int fork(void)
{
        int c;
        scanf("%i", &c)

---

There are also a few other points in my previous post that you haven't implemented yet -- consider re-reading it.

I have put it together and think it should now work, however I am getting linking errors that I can't understand... they are:

1>Linking...
1>Code.obj : error LNK2019: unresolved external symbol "void __cdecl restart(void)" (?restart@@YAXXZ) referenced in function "int __cdecl counter(char * const,int)" (?counter@@YAHQADH@Z)
1>Code.obj : error LNK2019: unresolved external symbol "int __cdecl readletter2(char,int)" (?readletter2@@YAHDH@Z) referenced in function "void __cdecl sort(char * const)" (?sort@@YAXQAD@Z)
1>Code.obj : error LNK2019: unresolved external symbol "void __cdecl readkeyboard(void)" (?readkeyboard@@YAXXZ) referenced in function "void __cdecl choice(void)" (?choice@@YAXXZ)
1>Code.obj : error LNK2019: unresolved external symbol "int __cdecl total(int)" (?total@@YAHH@Z) referenced in function _main
1>\\regent\user\ELT\rjt31\My Documents\Visual Studio 2005\Projects\Mini Project\Debug\Mini Project.exe : fatal error LNK1120: 4 unresolved externals

can you help???

Code:

---


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

enum count {CountM, CountD, CountC, CountL, CountX, CountV, CountI, CountCM, CountCD, CountXC, CountXL, CountIX, CountIV};

int count [13];

char LETTERS[16];

void restart ();       
int total (int);
int countless (int);
int counter (char, int);
int readletter2 (char, int);
int COUNT (int, int);
void sort (char);                                // converts the NUMERALS into counts
void readkeyboard ();                                        // reads the string from the keyboard
void ask ()        ;                                        // asks for input type
void choice();                                                // choose between file or keyboard


void RESTART ()                        // RESTARTS THE WHOLE PROGRAMME
{
        int yn;
        printf("Do you wish to try again? Enter Y to continue \n(else enter anything else to quit): ");
        scanf("%i", &yn);

        if(tolower(yn) == 'y')
        {
                ask ();
                choice();
        }
}

int total (int count[13])
{
        return ((count[0]*1000) + (count[1]*500) + (count[2]*100) + (count[3]*50) + (count[4]*10)
                + (count[5]*5) + (count[6]) + (count[7]*900) + (count[8]*400) + (count[9]*90) + (count[10]*40)
                + (count[11]*9) + (count[12]*4));
}

int countless (int a)
{
        a --;
        return a;
}

int counter (char Tab[16], int i)  // TALLIES AND ERROR CHECKS THE DOUBLE NUMERAL COUNTS
{       
        int REP;
        switch (Tab[i])
        {
        case '\0':
                break;
        case 'M':
                REP = 1; countless(count[CountC]); COUNT(count[CountCM], REP); break;
        case 'D':
                REP = 1; countless(count[CountC]); COUNT(count[CountCD], REP); break;
        case 'C':
                REP = 1; countless(count[CountX]); COUNT(count[CountXC], REP); break;       
        case 'L':
                REP = 1; countless(count[CountX]); COUNT(count[CountXL], REP); break;
        case 'X':
                REP = 1; countless(count[CountI]); COUNT(count[CountIX], REP); break;
        case 'V':
                REP = 1; countless(count[CountI]); COUNT(count[CountIV], REP); break;
        default:
                printf("You have input an invalid character");
                restart ();
        }
        return i;
}


int readletter2 (char Tab[16], int i)                // READS THE SECOND THE SECOND NUMERAL AFTER THE PRIMARIES C, X and I AND PERFORMS TALL
{       
        i ++;       
        counter (Tab, i);
        return i;
}

int COUNT (int i, int rep)                        // CHECKS AND TALLIES THE SINGLE NUMERAL COUNTS
{
        i ++;
        if (i > rep)
        {
                printf("You have input too many consecutive numerals");
                restart();
        }
        return i;
}

void sort (char Tab[])
{
        int i;
        int REP;

        for (i = 0; Tab[i] != '\0'; i++);

                {       
                        switch (Tab[i])
                        {
                                case 'M':
                                        REP = 4; COUNT(count[CountM], REP); break;
                                case 'D':
                                        REP = 1; COUNT(count[CountD], REP); break;
                                case 'C':
                                        REP = 3; COUNT(count[CountC], REP); readletter2(Tab[i], i); break;
                                case 'L':
                                        REP = 1; COUNT(count[CountL], REP); break;
                                case 'X':
                                        REP = 3; COUNT(count[CountX], REP); readletter2(Tab[i], i); break;
                                case 'V':
                                        REP = 1; COUNT(count[CountV], REP); break;
                                case 'I':
                                        REP = 3; COUNT(count[CountI], REP); readletter2(Tab[i], i); break;
                                default:
                                        printf("You have input an invalid character");
                                        restart ();
                        }
                }               
}

void readkeyboard (char Tab[16])                        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
{                                                                        //and change string to upper case       
        int x;
        int len = strlen(LETTERS);

        printf("\n Please input your ROMAN NUMERALS from the keyboard: ");
        scanf("%s", LETTERS);
        for (x=0; x<len; ++x)
        {
                LETTERS[x] = toupper(LETTERS[x]);
        }
}

void ask ()
{
        printf("\n Choose 1 for FILE input");
        printf("\n Choose 2 for KEYBOARD input: ");
}       

void choice(void)
{
        int c;
        do
        {
                scanf("%i", &c);
        }               
        while ((c <=0) || (c >=3));       

        if (c == 1)
                printf("You have chosen one - file input");
        else if (c == 2)
        {
                printf("You have chosen two - file input");        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
                readkeyboard ();
        }
}

int main ()
{                        // DECLARE VARIABLES ETC...
        int answer = 0;

        // CHOOSE BETWEEN KEYBOARD & BATCH MODE

        ask();
        choice();
        sort (LETTERS);
        answer = total(count[13]);

        printf("\n The value you input in ROMAN NUMERALS was: %s", LETTERS);
        printf("\n The equivalent value in Arabic numbers is: %i", answer);
}

---

RESTART is different from restart (and you should really change your name to "restart" for the actual function implementation, rather than the call to restart to RESTART, as upper case names are commonly used for macro names, not function names).

C++ is picky about function prototypes and the declaration of the function, including arguments:

Code:

---

int readletter2 (char, int);
...
int readletter2 (char Tab[16], int i);

---

That is two different functions - one is probably more right than the other. The compiler thinks you are using the first one, but you define the second one.

And similar problem with readkeyboard and total.
--
Mats

Because your function declarations are wrong:

Code:

---

void restart ();        /* Your actual function name is RESTART, which is not the same as restart. */
int total (int); /* Should be int total(int[13]); */
int readletter2 (char, int); /* Should be int readletter2(char[16], int); */
void readkeyboard (); /* Should be void readkeyboard(char[16]); */

---

You must make sure your definitions of your functions and declarations match, or you'll get a compile or linking error.

I think I was a bit out of my league with all those functions... I have reduced them down and put a lot more of the programme into main.

It all works but I keep getting the default message from the switch whenever I input a string no matter what - it doesn't sort though properly :( . I can't understand how it is missing the numerals in the string...

Please please help me...

Code:

---


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

enum count {CountM, CountD, CountC, CountL, CountX, CountV, CountI, CountCM, CountCD, CountXC, CountXL, CountIX, CountIV};

char LETTERS[16];


void initialise (char []);
void initialize (int []);
void restart ();       
void readkeyboard();                                        // reads the string from the keyboard
void ask ()        ;                                        // asks for input type
void choice();                                                // choose between file or keyboard


void initialize (int tab[])
{
        int i;
        for (i=0; i<=15; ++i)
                tab[i] = 0;
}

void initialise (char tab[])
{
        int i;
        for (i=0; i<=15; ++i)
                tab[i] = 0;
}


void restart ()                        // RESTARTS THE WHOLE PROGRAMME
{
        int yn;
        printf("Do you wish to try again? Enter Y to continue \n(else enter anything else to quit): ");
        scanf("%i", &yn);

        if(tolower(yn) == 'y')
        {
                ask ();
                choice();
        }
}


void readkeyboard ()                        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
{                                                                        //and change string to upper case       
        int x;
        int len = strlen(LETTERS);

        printf("\n Please input your ROMAN NUMERALS from the keyboard: ");
        scanf("%s", LETTERS);
        for (x=0; x<len; ++x)
        {
                LETTERS[x] = toupper(LETTERS[x]);
        }
}

void ask ()
{
        printf("\n Choose 1 for FILE input");
        printf("\n Choose 2 for KEYBOARD input: ");
}       

void choice(void)
{
        int c;
        do
        {
                scanf("%i", &c);
        }               
        while ((c <=0) || (c >=3));       

        if (c == 1)
                printf("You have chosen one - file input");
        else if (c == 2)
        {
                printf("You have chosen two - file input");        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
                readkeyboard ();
        }
}

int main ()
{                        // DECLARE VARIABLES ETC...
        int answer = 0;
        int total;
        int i;
        int REP;
        int count [13];

        // CHOOSE BETWEEN KEYBOARD & BATCH MODE

        initialise (LETTERS);
        initialize (count);
        ask();
        choice();
       
       
        for (i = 0; LETTERS[i] != '\0'; i++);

                {       
                        switch (LETTERS[i])
                        {
                                case 'M':
                                        REP = 4;
                                        ++ count[CountM];
                                        if (count[CountM] > REP)
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }
                                        break;

                                case 'D':
                                        REP = 1;
                                        ++ count[CountD];
                                        if (count[CountD] > REP)       
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }                                       
                                        break;

                                case 'C':
                                        REP = 3;
                                        ++ count[CountC];
                                        if (count[CountC] > REP)       
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }       

                                        i ++;
                                        REP = 1;

                                        switch (LETTERS[i])
                                        {               
                                        case '\0':
                                                break;
                                        case 'M':
                                                -- count[CountC]; ++ count[CountCM];

                                                if (count[CountCM] > REP)       
                                                {
                                                        printf("You have input too many consecutive numerals");
                                                        restart();
                                                }                       
                                                break;
                                       
                                        case 'D':
                                                -- count[CountC]; ++ count[CountCD];
                                                if (count[CountCD] > REP)       
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }       
                                                break;
                                        }
                                        break;

                                case 'L':
                                        REP = 1;
                                        ++ count[CountL];
                                        if (count[CountL] > REP)       
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }       
                                        break;

                                case 'X':
                                        REP = 3;
                                        ++count[CountX];
                                        if (count[CountX] > REP)       
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }       

                                        i ++;
                                        REP = 1;

                                        switch (LETTERS[i])
                                        {               
                                        case '\0':
                                                break;
                                        case 'C':
                                                -- count[CountX]; ++ count[CountXC];

                                                if (count[CountXC] > REP)       
                                                {
                                                        printf("You have input too many consecutive numerals");
                                                        restart();
                                                }                       
                                                break;
                                       
                                        case 'L':
                                                -- count[CountX]; ++ count[CountXL];
                                                if (count[CountXL] > REP)       
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }       
                                                break;
                                        }
                                        break;

                                case 'V':
                                        REP = 1;
                                        ++ count[CountV];
                                        if (count[CountV] > REP)       
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }       
                                        break;

                                case 'I':
                                        REP = 3;
                                        ++ count[CountI];
                                        if (count[CountI] > REP)       
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }       

                                        i ++;
                                        REP = 1;

                                        switch (LETTERS[i])
                                        {               
                                        case '\0':
                                                break;

                                        case 'X':
                                                -- count[CountI]; ++ count[CountIX];

                                                if (count[CountIX] > REP)       
                                                {
                                                        printf("You have input too many consecutive numerals");
                                                        restart();
                                                }                       
                                                break;
                                       
                                        case 'D':
                                                -- count[CountI]; ++ count[CountIV];
                                                if (count[CountIV] > REP)       
                                        {
                                                printf("You have input too many consecutive numerals");
                                                restart();
                                        }       
                                                break;
                                        }
                                        break;

                                default:
                                        printf("You have input an invalid character");
                                        restart ();
                        }
                }       

        total = ((count[CountM]*1000) + (count[CountD]*500) + (count[CountC]*100) + (count[CountL]*50) + (count[CountX]*10)
                + (count[CountV]*5) + (count[CountI]) + (count[CountCM]*900) + (count[CountCD]*400) + (count[CountXC]*90) + (count[CountXL]*40)
                + (count[CountIX]*9) + (count[CountIV]*4));

        printf("\n The value you input in ROMAN NUMERALS was: %s", LETTERS);
        printf("\n The equivalent value in Arabic numbers is: %i", total);
}

---

roman numerals in the string - sorry not numbers... please help :(

You're mixing C and C++. Which one do you want?
Also, avoid global variables and just use ZeroMemory or memset to initialize your variables or just do

Code:

---

char somearray[10] = {0};

---

I want C, but posted in the wrong forum...

AFAIK, overloading functions is not supported in C. I'm surprised the compiler will even allow that.

So should I try and get rid of all functions? The reason I started using functions was to make it neater but also to allow me to start again if there was an error detected. Only in my first term of programming so not really 100&#37; about anything at the moment...

Code:

---

void initialise (char []);
void initialize (int []);

---

Not allowed because they have the same name but different parameters. Valid in C++, but not C.

Also I need a file read in or input from keyboard - and could not figure out how to do it without duplicating the code with a massive if???

Quote:

---

Originally Posted by Elysia

Code:

---

void initialise (char []);
void initialize (int []);

---

Not allowed because they have the same name but different parameters. Valid in C++, but not C.

---

I spelt one with an 's' and one with a 'z'...

Not sure what you're hinting at?

Quote:

---

Originally Posted by DonGenaro

I spelt one with an 's' and one with a 'z'...

---

I see, very subtle difference there. I don't think that's a good idea at all. Consider renaming them.

Quote:

---

Originally Posted by DonGenaro

Code:

---


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

enum count {CountM, CountD, CountC, CountL, CountX, CountV, CountI, CountCM, CountCD, CountXC, CountXL, CountIX, CountIV};

char LETTERS[16]; /* Don't use global variables! */

/* Consider renaming. */
void initialise (char []);
void initialize (int []);
/* All functions that takes no params should take void in C */
void restart ();       
void readkeyboard();                                        // reads the string from the keyboard
void ask ()        ;                                        // asks for input type
void choice();                                                // choose between file or keyboard



/* Use ZeroMemory or memset. Much easier and will alow you to avoid these superflous functions */
void initialize (int tab[])
{
        int i;
        for (i=0; i<=15; ++i)
                tab[i] = 0;
}

void initialise (char tab[])
{
        int i;
        for (i=0; i<=15; ++i)
                tab[i] = 0;
}


void restart ()                        // RESTARTS THE WHOLE PROGRAMME
{
        int yn; /* You want to read a char, not an int */
        printf("Do you wish to try again? Enter Y to continue \n(else enter anything else to quit): ");
        scanf("%i", &yn); /* Should be scanf("%c", &yn); because you want to read a char, not an int */

        if(tolower(yn) == 'y')
        {
                ask ();
                choice();
        }
}


void readkeyboard ()                        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
{                                                                        //and change string to upper case       
        int x;
        int len = strlen(LETTERS);

        printf("\n Please input your ROMAN NUMERALS from the keyboard: ");
        scanf("%s", LETTERS); /* scanf is very unsafe for reading strings. Consider using fgets. */
        for (x=0; x<len; ++x)
        {
                LETTERS[x] = toupper(LETTERS[x]);
        }
}

void choice(void)
{
        int c;
        do
        {
                scanf("%i", &c);
        }               
        while ((c <=0) || (c >=3));       

        if (c == 1)
                printf("You have chosen one - file input");
        else if (c == 2)
        {
                printf("You have chosen two - file input");        // FOR KEYBOARD MODE ASK FOR NUMERALS AND COPY INTO "LETTERS"
                readkeyboard ();
        }
}

int main ()
{                        // DECLARE VARIABLES ETC...
        int answer = 0;
        int total;
        int i;
        int REP;
        int count [13];

        // CHOOSE BETWEEN KEYBOARD & BATCH MODE

        /* Consider initializing directly in main instead of making small functions for such small code... it doesn't really matter */
        initialise (LETTERS);
        initialize (count);
        /* I don't agree with this - put it in ONE function instead. It's easier to read the code if you ask the question AND take the answers for it in the same function */
        ask();
        choice();
/* ... */
}

---

---

Some mistakes/corrections you could make. See comments in red.

It is very bad to use subtle differences in function names (such as "initialize" and "initialise"). It is almost impossible to see the difference without reading each individual letter. If you want to make two functions different, use prefix or postfix, e.g.

For example:

Code:

---

InitializeInt();
InitializeChar();

---

or

Code:

---

CharInitialize();
IntInitialize();

---

As Elysia says, using either:

Code:

---

int count[16] = { 0 };

---

or

Code:

---

memset(count, 0, sizeof(count));

---

would be much better.

[Don't use ZeroMemory, that is a windows specifc function, and you only want to use such functions when the entire file only contains windows-specific code]

Not to mention that your code in initialize is broken:

Code:

---

int count [13];

void initialize (int tab[])
{
        int i;
        for (i=0; i<=15; ++i)
                tab[i] = 0;
}

---

You have 13 elements, but you initialize 16.

--
Mats

Many thanks for all your help. I have decided to steer clear of functions - don't understand parsing/passing well enough yet...

What I have done seems to work, although it is more scrappy... The only thing that doesn't work is reading the file in but I don't not whether thats how its being executed or the code.

Many thanks for all your help. When I get a little better and can help others I surely will...

Code:

---


#include <stdio.h>
#include <stdlib.h>


int main (void)

{

char tab[16];
int REP;
int i;
int z;
int total;
int c;
int unreal = 0;
FILE *file_in;
FILE *file_out;


int CountM, CountD, CountC, CountL, CountX, CountV, CountI, CountCM, CountCD, CountXC, CountXL, CountIX, CountIV;

CountM = CountD = CountC = CountL = CountX = CountV = CountI = CountCM = CountCD = CountXC = CountXL = CountIX = CountIV = 0;


for (z=0; z<=15; ++z)
        {
                tab[z] = 0;
        }

        printf("\nChoose 1 for FILE input");
        printf("\nChoose 2 for KEYBOARD input: ");

        do
        { 
                scanf("%i", &c);
        }                               
        while ((c <=0) || (c >=3));       

        if (c == 1)
        {
                printf("You have chosen one - file input"); //STILL NEED TO FIGURE OUT CODE TO INPUT A STRING VIA A FILE

                {
                        file_in = fopen("Roman.txt","r");
                        fscanf(file_in, "%s", tab);
                        fclose(file_in);
                        return 0;
                }
        }

        else if (c == 2)
        {
                printf("You have chosen two - file input");        // (KEYBOARD MODE) ASK FOR NUMERALS AND COPY INTO "LETTERS"
               
                printf("\nPlease input your ROMAN NUMERALS from the keyboard: ");
                scanf("%s", tab);
        }
               
                for (i=0; tab[i] != '\0';i++)

                switch (tab[i])
                        {
                                case 'M':
                                        REP = 4;
                                        CountM ++;
                                        if (CountM > REP)
                                        {
                                                printf("ERROR: You have input too many M's");
                                                unreal = 1;
                                        }
                                        break;

                                case 'D':
                                        REP = 1;
                                        CountD ++;
                                        if (CountD > REP)       
                                        {
                                                printf("ERROR: You have input too many D's");
                                                unreal = 1;
                                        }                                       
                                        break;

                                case 'C':
                                        i++;
                                        REP = 3;
                                        CountC ++;
                                        if (CountC > REP)       
                                        {
                                                printf("ERROR: You have input too many C's");
                                                unreal = 1;
                                        }       

                                        REP = 1;
                                        switch (tab[i])
                                        {               
                                        case '\0':
                                                break;
                                        case 'M':
                                                i++;
                                                CountC --; CountCM ++;

                                                if (CountCM > REP)       
                                                {
                                                        printf("ERROR: You have input too many CM's");
                                                unreal = 1;
                                                }
                                                break;
                                       
                                        case 'D':
                                                i++;
                                                CountC --;  CountCD ++;
                                                if (CountCD > REP)       
                                        {
                                                printf("ERROR: You have input too many CD's");
                                                unreal = 1;
                                        }       
                                                break;
                                        }i --;
                                        break;

                                case 'L':
                                       
                                        REP = 1;
                                        CountL ++;
                                        if (CountL > REP)       
                                        {
                                                printf("ERROR: You have input too many L's");
                                                unreal = 1;
                                        }       
                                        break;

                                case 'X':
                                        i++;
                                        REP = 3;
                                        CountX ++;
                                        if (CountX > REP)       
                                        {
                                                printf("ERROR: You have input too many X's");
                                                unreal = 1;
                                        }       

                                        REP = 1;

                                        switch (tab[i])
                                        {               
                                        case '\0':
                                                break;
                                        case 'C':
                                                i++;
                                                CountX -- ;  CountXC ++;

                                                if (CountXC > REP)       
                                                {
                                                        printf("ERROR: You have input too many XC's");
                                                unreal = 1;
                                                }               
                                                break;
                                       
                                        case 'L':
                                                i++;
                                                CountX -- ;  CountXL ++;
                                                if (CountXL > REP)       
                                        {
                                                printf("ERROR: You have input too many XL's");
                                                unreal = 1;
                                        }       
                                                break;
                                        }i--;
                                        break;

                                case 'V':
                                        REP = 1;
                                        ++ CountV;
                                        if (CountV > REP)       
                                        {
                                                printf("ERROR: You have input too many V's");
                                                unreal = 1;
                                        }       
                                        break;

                                case 'I':
                                        i++;
                                        REP = 3;
                                        ++ CountI;
                                        if (CountI > REP)       
                                        {
                                                printf("ERROR: You have input too many I's");
                                                unreal = 1;
                                        }       

                                        REP = 1;

                                        switch (tab[i])
                                        {               
                                        case '\0':
                                                break;

                                        case 'X':
                                                i++;
                                                CountI -- ; CountIX ++ ;

                                                if (CountIX > REP)       
                                                {
                                                        printf("ERROR: You have input too many IX's");
                                                unreal = 1;
                                                }               
                                                break;
                                       
                                        case 'D':
                                                i++;
                                                CountI --; CountIV ++ ;
                                                if (CountIV > REP)       
                                        {
                                                printf("ERROR: You have input too many IV's");
                                                unreal = 1;
                                        }       
                                                break;
                                        }i--;
                                        break;

                                default:
                                        printf("You have input an invalid character");
                                       
                        }
       
        //CALCULATE THE TOTAL OF ALL THE COUNTS MULTIPLIED AGAINST THEIR EQUIVALENT ARABIC VALUE

        total = ((CountM*1000) + (CountD*500) + (CountC*100) + (CountL*50) + (CountX*10)
                + (CountV*5) + (CountI) + (CountCM*900) + (CountCD*400) + (CountXC*90) + (CountXL*40)
                + (CountIX*9) + (CountIV*4));

        if (c == 1)
        {
                printf("You have chosen one - file input"); //STILL NEED TO FIGURE OUT CODE TO INPUT A STRING VIA A FILE

                {
                        file_out = fopen("new.txt","w");
                        fprintf(file_out, "%i", total);
                        fclose(file_out);
                        return 0;
                }
        }

        //PRINT THE ORIGINAL ROMAN NUMERAL AND THE ARABIC CONVERTED VALUE

        printf("\n The value you input in ROMAN NUMERALS was: %s", tab);
        if (unreal == 0)
                printf("\n The equivalent value in Arabic numbers is: %i", total);
        else
                printf("\n The possible equivalent value of your BADLY CONSTRUCTED ROMAN NUMERAL in Arabic numbers is: %i", total);
        }

---

Steer clear of functions is probably not really the right approach. That's like saying "because using a hammer to fit a piece of glass broke the glass, I won't use a hammer ever again".

Using the right tool for the job is what it's all about. Functions are great for splitting a task into smaller sections.

Learning how to split a task into smaller sections is all part of programming.

Your code as it stands now is a bit too complex, in my opinion. You could certainly make it better by splitting it up.

In this case, you could also use a table that contains the single or multiple letters [e.g. C, M, IX, CM, etc], the repeat count, and the value for that particlar piece of roman numbers, and then use that table to parse the number, instead of your huge switch statement. Just make sure you check for CM and such before you look for C [simply done by placing those earlier in the table than the "plain" digits].

--
Mats

Don't use fscaf for reading strings - it's unsafe. Use fgets instead.
As for reading/writing to files, you're getting there. Remember to check for NULL in your stream returned by fopen. If fopen fails and you call another function, your program will crash trying to read memory from NULL (which will crash on any x86 system).
When reading, once again, use fgets. When writing, you can use fputs (saves a string to the stream).

Quote:

---

Originally Posted by matsp

In this case, you could also use a table that contains the single or multiple letters [e.g. C, M, IX, CM, etc], the repeat count, and the value for that particlar piece of roman numbers, and then use that table to parse the number, instead of your huge switch statement.
Mats

---

Could you possibly give me a small example of how I might set up such a table as I haven't yet covered them. I had a look at them but got a bit confused. Maybe if you are unable to give an example you could possibly give me a link to some more information on the subject... with examples

Many thanks again.

And thanks Elysia I am looking into fgets...

Code:

---

struct RomanValue
{
    std::string num;
    int  value;
    int  maxRep;
};

RomanValue romanValues[] =
{
  {"CM", 900, 1 },
  { "M", 1000, 4 },
  { "C", 100, 3 },
  ....
};

---

--
Mats