Need help to fix function to be used in main

I am trying to have my function return # of repeated letters in a strg. Ex. mississippi has 3:i,s,p(can't count repeats) I am getting no errors but can't figure out how to get the right answer. If anyone can help thanks.

Code:

 
#include <stdio.h>
int repeat(char *ptr)
{ 
 int count=0,count2,i,n=26,k=0; 
 char x[]="abcdefghijklmnopqrstuvwxyz";     
 for(i=0; i<n; i++)
 {    
  count2=0;
  while(*ptr != '\0')
  {    
   if ((*ptr=x[i]))
    count2++;
   ptr++; k++;
   if (count2==2)
    count++;
  }
  ptr-=k;
 }
return count;
} 
int main( void)
{
 int e=0;
  char strg[]="mississippi";
  printf("before repeat: %d \n", e);
 e=repeat(strg);
 printf("after repeat: %d \n", e); 
return 0;
}

Code:

if ((*ptr=x[i]))

There's your problem, you are assigning instead of comparing.

Ive toggled between = and ==. If i simplfy the code down just to count strg length with ==, it returns 0 with = it returns 11. Thanks for reply though.

That's because

Code:

if ((*ptr=x[i]))
    count2++;

will always be true, so the counter will click over. You have to compare using ==. I think the bug is in the incrementing and subtraction of the pointer values.

It is returning 0 even when i reduce it to:

Code:

if (*ptr==x[i])
count++;
*ptr++;

The answer would be 11 but only return 11 when i use single.

Code:

int repeat(char *ptr)
{ 
 int count = 0, count2, i, n = 26, k = 0; 
 char *ref = ptr;
 char x[]="abcdefghijklmnopqrstuvwxyz";     
 
 for( i = 0; i < n; i++ )
 {    
  count2 = 0;
  
  while( *ptr != '\0' )
  {    
       if ( *ptr == x[i] )
       {
            count2++;
       }
       
       ptr++;
       k++;
       
       if ( count2 == 2 )
       {
            count++;
       }
  }
  
  ptr = ref;
 
 }
return count;
}

There were issues with the subtraction of pointers. It's easier just to save a copy of the original. It's still buggy, but you should be able to move on from this problem.

Items in red are things I changed - in blue, I removed.

That last reply really helped me, Thanks alot.