Thread: Word Sort

Hello!

I have written this code which is supposed to take five names as input and then arrange them in alphabetical order. It got compiled easily but after I input those 5 names, the window closes automatically even when I have getch() in place. Also, I don't think I have written the function which sorts the names [word_swap()] any good.

Please help me set this code right....(I know ive made a mess, sorry for that )

Thanks!

Code:

#include<stdio.h>
#include<conio.h>
void word_swap(char*,char*);  /*I don't think I have written the definition of this function correctly*/
int main()
{
    char temp[20],names[5][20];
    int x,y,z;
    for(x=0;x<5;x++)
    {
                    printf("\nEnter a name :");
                    scanf("&#37;s",&temp);
                    for(y=0;names[x][y]!='\0';y++)
                    {
                                                 names[x][y]=temp[y];
                    }
                    names[x][y]='\0';
    }
    
    for(x=0;x<5;x++)
    {
             for(z=x+1;z<5;z++)
             {
                               for(y=0;names[x][y]!='\0'&& names[z][y] !='\0';y++)
                               {
                                                           if((int)names[x][y]>(int)names[z][y])
                                                           word_swap(&names[x][0],&names[z][0]);
                               }
             }
    }
    for(x=0;x<5;x++)
    {
                    
                    printf("\n");
                    for(y=0;names[x][y]!='\0';y++)
                                                  printf("%c",names[x][y]);
    }
    
    getch();
    return 0;
}


void word_swap(char*str1,char*str2)
{
     int n=0;
     char temp;
     while(n!=2)
     {
               temp=*str1;
               *str1=*str2;
               *str2=temp;
                str1++;
                str2++;
                if(*str1=='\0')
                               n++;
                if(*str2=='\0')
                               n++;
     }
                                        
}

Better to use fgets instead of scanf to read strings. Scanf can be dangerous when reading strings as well. See my signature.
And you could really use some less spaces for each indentation level. 4 is more than enough.

Post your updated code please.

Originally Posted by abk

Have i written the word_swap() definition correctly ?

If you are referring to the prototype void word_swap( char *, char * ); Yes it it correct. The compiler only needs to know that
word_swap accepts two string pointers.

fgets() will read up to 19 characters and it will insert a '\0' at the end of the string.
some possibilities:
You enter a name sorter or up to 18 characters, fgets reads everything including the ENTER key (newline) and attachs a terminator '\0' at the ending.

You enter a name exactly 19 long and press enter. fgets reads those characters, terminates it with '\0' and leaves ENTER key behind for the next call to pick it up.

You enter a name longer that 20 characters. Any thing beyond 19 characters is left in the buffer input, including the ENTER key.

BTW, I am assuming you are practicing loops and accessing subscripts of arrays. Because there's already standard functions that will do the same thing you're trying to achieve.

After you find what's the problem closing your program right away, we'll talk about why your code will not do what you intend.

Come on, abk, you use way too many spaces for indentation. Lessen it a bit. It makes it look nicer and people don't have to scroll to read the code. It's very simple.

Your lexicographical ordering is wrong.
word_swap should not be within 3 nested loops. Right now it might swap two words many times over. The inner loop should be replaced with a strcmp.
Then you can find out what order the words should be in and THEN decided ONCE whether to swap them or not.

If I may suggest.
Write small pieces of code and compile often.
e.g
Write the part that will get the input into an array of strings. ( It is not necessary to go through a temporal string variable )
Compile.
Write a test loop that will display each string
Compile.
Notice the unwanted newline in each string.
Write the part that will eliminate the newline in each string.
Compile.
In a different file write a function that swap strings
Compile.
Test the function. If is bug free, add to the project
writing the part that loops through the strings and compare them.
Compile.
Debugging will be easier when you have tested every little portion and know that is working the way intended.

BTW You don't need #include<conio.h> and getch. A simple standard getchar() would do very well.