Counting quantity of different digits

What I'm doing wrong . . .
I need to count quantity of different digits in number
for example 321123 : and output i want like that

There r 3 different digits in the number 321123

Code:

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while(n)
 
          {  dif=n%10;
          n/=10;
          if (dif=n%10)
                  n/=10;
          else
          count++;
          }
          printf("\nThere r  ",count);
          printf(" different digits in the number",n);

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Code:

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#include <stdio.h>

int main() {
        int n=321123, copy = n, r, counts[10] = {0}, digits = 0;
        while (copy) {
                r = copy%10;
                counts[r]++;
                copy /= 10;
        }

        for (r=0;r<10;r++) {
                if (counts[r]) {
                        printf("%d %d's\n",counts[r],r);
                        digits++;
                }
        }

        printf("%d contains %d different digits.\n",n,digits);
        return 0;
}

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