Simple enough task

Hi all,
1st time poster.

I have a fairly simple task that I need to carry out, however I am not terribly good at C programming, so bare with me!!!!
Basically I need to take in a string of 15 binary bits, from this input I will be adding bits 1,6,11 bits 2,7,12 bits 3,8,13 bits 4,9,14 and bits 5,10,15.
These will all give me parity which will either be a 0 or a 1. I then have to output the original 15 bits along with the 5 new bits, so my output will be 20 bits long.

I hope that all makes sense.......so far I have been trying to do it as such........

Code:

---

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

int main()
{
        int codeword_array[20];
        int i=0;

        printf("Welcome to the 5-bit parity code calculator\nPlease enter the 1st bit of the 15 bit codeword now: \n");
       
        for (int i>=0; i<16; i++)
        {
                int bit_array[i];       
                scanf("%d", bit_array[i])
                        if bit !=(0||1)
                        {
                                printf("All bits must be 0 or a 1");
                        }
                        codeword_array[i] = bit[i];
        }       

        if (bit_array[0] + bit_array[5] + bit_array[10] = (0||2))
                {       
                        codeword_array[15] = 0;
                }
        else if (bit_array[0] + bit_array[5] + bit_array[10] = (1||3))
                {
                        codeword_array[15] = 1;       
                }       
        else
                {
                        printf("Error\n");
                }
        system("pause");
        return 0;
}

---

The thinking behind this is that if I use a 20 bit array, and start off filling the 1st 15 blocks, then do the parity check on them and with my answers fill the final 5.
However I am getting a good few errors on this.

Hope someone can help.

Regards,

Niall.

Firt of all you should use == in your if statements. = is an assignment operator which means all your if tests will be true.

You also use "bit" but never declare it anywhere...

What errors are you getting?

Code:

---

(14) : error C2143: syntax error : missing ';' before 'type'
(14) : error C2143: syntax error : missing ';' before 'type'
(14) : error C2143: syntax error : missing ')' before 'type'
(14) : error C2143: syntax error : missing ';' before 'type'
(14) : warning C4552: '<' : operator has no effect; expected operator with side-effect
(14) : error C2059: syntax error : ')'
(15) : error C2143: syntax error : missing ';' before '{'
(16) : error C2057: expected constant expression
(16) : error C2466: cannot allocate an array of constant size 0
(16) : error C2133: 'bit_array' : unknown size
(18) : error C2143: syntax error : missing ';' before 'if'
(18) : error C2061: syntax error : identifier 'bit'
(22) : error C2109: subscript requires array or pointer type
(25) : error C2059: syntax error : 'if'
(29) : error C2059: syntax error : 'else'
(33) : error C2059: syntax error : 'else'
(39) : error C2143: syntax error : missing ')' before 'string'
(39) : error C2143: syntax error : missing '{' before 'string'
(39) : error C2059: syntax error : '<Unknown>'
(39) : error C2059: syntax error : ')'
(40) : error C2059: syntax error : 'return'
(41) : error C2059: syntax error : '}'

---

These are all the errors, (after I changed the = to == and declared bit) A lot of them seem to be linked to the one thing, so I think I might just be missing something simple thats causing a lot of them!!!

P.s. I declared bit outside the for loop, is this correct?

Code:

---

int codeword_array[20];
        int i=0;
        int bit;

        printf("Welcome to the 5-bit parity code calculator\nPlease enter the 1st bit of the 15 bit codeword now: \n");
       
        for (int i>=0; i<16; i++)

---

you need to use a & before bit_array[i] in your scanf statement.

And you need a ; after the scanf line too.

compile again and post your errors.

Ok, that got rid of a couple, thanks for that. The next one's are:

Code:

---

(14) : error C2143: syntax error : missing ';' before 'type'
(14) : error C2143: syntax error : missing ';' before 'type'
(14) : error C2143: syntax error : missing ')' before 'type'
(14) : error C2143: syntax error : missing ';' before 'type'
(14) : warning C4552: '<' : operator has no effect; expected operator with side-effect
(14) : error C2059: syntax error : ')'
(15) : error C2143: syntax error : missing ';' before '{'
(16) : error C2057: expected constant expression
(16) : error C2466: cannot allocate an array of constant size 0
(16) : error C2133: 'bit_array' : unknown size
(18) : error C2061: syntax error : identifier 'bit'
(22) : error C2109: subscript requires array or pointer type
(25) : error C2059: syntax error : 'if'
(29) : error C2059: syntax error : 'else'
(33) : error C2059: syntax error : 'else'
(39) : error C2143: syntax error : missing ')' before 'string'
(39) : error C2143: syntax error : missing '{' before 'string'
(39) : error C2059: syntax error : '<Unknown>'
(39) : error C2059: syntax error : ')'
(40) : error C2059: syntax error : 'return'
(41) : error C2059: syntax error : '}'

---

There seems to be a good few on line 14. Line 14 is the beginning of the for loop,

Code:

---

        for (int i>=0; i<16; i++)

---

Sorry about this, I know its very messy, but just trying to get my head around it!!

the fist part of the for statement sets the intial value of i.

for (int i = 0; i<16; i++) will loop from 0 - 15

Ok, thats grand thanks,

But still giving the errors that i'm missing ;'s around line 14. Dunno where this is happening though,

Any ideas?

post your fixed code

Code:

---

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

int main()
{
       
        int codeword_array[20];
        int i=0;
        int bit;

        printf("Welcome to the 5-bit parity code calculator\nPlease enter the 1st bit of the 15 bit codeword now: \n");
       
        for (int i = 0; i<16; i++)
        {
                int bit_array[i];       
                scanf("%d", &bit_array[i]);
                        if bit !==(0||1)
                        {
                                printf("All bits must be 0 or a 1");
                        }
                        codeword_array[i] = bit[i];
        }       

        if (bit_array[0] + bit_array[5] + bit_array[10] == (0||2))
                {       
                        codeword_array[15] == 0;
                }
        else if (bit_array[0] + bit_array[5] + bit_array[10] == (1||3))
                {
                        codeword_array[15] == 1;       
                }       
        else
                {
                        printf("Error\n");
                }
       
       
        system("pause");
        return 0;
}

---

You can't declare bit_array inside the for loop. Doing so will declare it each iteration.

You test bit after the scanf, but never assign bit a value. You should do...

Code:

---

scanf("%d", &bit);
if (bit != 0 && bit !=1)
{
  printf("All bits...");
}
else
{
  codeword_array[i] = bit;
}

---

You don't need bit_array at all. Change bit_array in your subsequent if statements to codeword_array.

Ok, should it be declared globally? I have done it like this now....

Code:

---

int codeword_array[20];
        int i=0;
        int bit;
        int bit_array[i];       

        printf("Welcome to the 5-bit parity code calculator\nPlease enter the 1st bit of the 15 bit codeword now: \n");
       
        for (int i = 0; i<16; i++)
        {               
                scanf("%d", &bit_array[i]);
                        if bit !==(0||1)
                        {
                                printf("All bits must be 0 or a 1");
                        }
                        codeword_array[i] = bit[i];
        }       

        if (bit_array[0] + bit_array[5] + bit_array[10] == (0||2))
                {       
                        codeword_array[15] == 0;
                }
        else if (bit_array[0] + bit_array[5] + bit_array[10] == (1||3))
                {
                        codeword_array[15] == 1;       
                }       
        else
                {
                        printf("Error\n");
                }
       
       
        system("pause");
        return 0;
}

---

With some new errors

Code:

---

(11) : error C2057: expected constant expression
(11) : error C2466: cannot allocate an array of constant size 0
(11) : error C2133: 'bit_array' : unknown size
(15) : error C2143: syntax error : missing ';' before 'type'
(15) : error C2143: syntax error : missing ';' before 'type'
(15) : error C2143: syntax error : missing ')' before 'type'
(15) : error C2143: syntax error : missing ';' before 'type'
(15) : warning C4552: '<' : operator has no effect; expected operator with side-effect
(15) : error C2059: syntax error : ')'
(16) : error C2143: syntax error : missing ';' before '{'
(18) : error C2061: syntax error : identifier 'bit'
(22) : error C2109: subscript requires array or pointer type
(25) : error C2059: syntax error : 'if'
(29) : error C2059: syntax error : 'else'
(33) : error C2059: syntax error : 'else'
(39) : error C2143: syntax error : missing ')' before 'string'
(39) : error C2143: syntax error : missing '{' before 'string'
(39) : error C2059: syntax error : '<Unknown>'
(39) : error C2059: syntax error : ')'
(40) : error C2059: syntax error : 'return'
(41) : error C2059: syntax error : '}'

---

Ok, had posted that last one before I realised there was a reply!!!!

Changing bit_array to codeword_array worked for a lot of them, down to 7 errors now.
code is

Code:

---

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

int main()
{
       
        int codeword_array[20];
        int i=0;
        int bit;
       
        printf("Welcome to the 5-bit parity code calculator\nPlease enter the 1st bit of the 15 bit codeword now: \n");
       
        for (int i = 0; i<16; i++)
        {               
                scanf("%d", &bit);
                if (bit != 0 && bit !=1)
                        {
                                printf("All bits must be a 0 or a 1/n");
                        }
                else
                        {
                                codeword_array[i] = bit;
                        }
               
               
       

        if (codeword_array[0] + codeword_array[5] + codeword_array[10] == (0||2))
                {       
                        codeword_array[15] = 0;
                }
        else if (codeword_array[0] + codeword_array[5] + codeword_array[10] == (1||3))
                {
                        codeword_array[15] = 1;       
                }       
        else
                {
                        printf("Error\n");
                }
       
       
        system("pause");
        return 0;
}

/*scanf( "%d", &bit1 );
       
        if ( bit1 != (0 || 1))
        {
                printf( "All bits must be either 0 or 1\n" );
        }
        else
        {       
                printf( "You entered %d", bit1);
        }

---

and the remaining errors are

Code:

---

(14) : error C2143: syntax error : missing ';' before 'type'
(14) : error C2143: syntax error : missing ';' before 'type'
(14) : error C2143: syntax error : missing ')' before 'type'
(14) : error C2143: syntax error : missing ';' before 'type'
(14) : warning C4552: '<' : operator has no effect; expected operator with side-effect
(14) : error C2059: syntax error : ')'
(15) : error C2143: syntax error : missing ';' before '{'
(43) : warning C4013: 'system' undefined; assuming extern returning int
(94) : fatal error C1075: end of file found before the left brace '{' at 'c:\users\niall\documents\college\4th year\2nd semester\ee402\5bit parity code\5bit parity code\source.c(6)' was matched

---

You don't need bit_array at all. If you're storing the bit array in codeword_array, why store it in bit_array too?

and you can't use [i] in the declaration.

you have declared i twice

cool, sorted that.
Just the end of file thing now.

Its quite strange, when I click the error its going right to the top of the code, inside the #include<stdio.h> line.

I'm sure this is just something silly but any ideas?

Code:

---

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

int main()
{
       
        int codeword_array[20];
        int i=0;
        int bit;
       
        printf("Welcome to the 5-bit parity code calculator\nPlease enter the 1st bit of the 15 bit codeword now: \n");
       
        for ( i = 0; i<16; i++)
        {               
                scanf("%d", &bit);
                if (bit != 0 && bit !=1)
                        {
                                printf("All bits must be a 0 or a 1/n");
                        }
                else
                        {
                                codeword_array[i] = bit;
                        }
               
               
       

        if (codeword_array[0] + codeword_array[5] + codeword_array[10] == (0||2))
                {       
                        codeword_array[15] = 0;
                }
        else if (codeword_array[0] + codeword_array[5] + codeword_array[10] == (1||3))
                {
                        codeword_array[15] = 1;       
                }       
        else
                {
                        printf("Error\n");
                }
       
       
        system("pause");
        return 0;
}

---

What is the error?

(46) : fatal error C1075: end of file found before the left brace '{' at 'c:\users\niall\documents\college\4th year\2nd semester\ee402\5bit parity code\5bit parity code\source.c(6)' was matched

Quote:

---

Originally Posted by niallheavey

(46) : fatal error C1075: end of file found before the left brace '{' at 'c:\users\niall\documents\college\4th year\2nd semester\ee402\5bit parity code\5bit parity code\source.c(6)' was matched

---

Are you surprised by that, given that you have seven opening braces and six closing braces?

You need another close bracket at the end. you never close the for loop bracket

I knew it was going to be something stupid.

Thank you very much for all the help.
Regards,

Niall.