Characters which appeared least

I find such a function, modified it a bit, but it seems to outputs argumnets which appeared the most, but I tried to make it outputs least appearing character.

 void leastOften(int *s) {
        int i, j;
        int min[256] = {0} ;
        int min_count = 1000;
        for (i=0; i<256; i++) {
            if (s[i]) {
                if (s[i] < min_count) {
                    for (j=0; j<256; j++)
                        min[j]=0;
                    min[i]=1;
                    min_count = s[i];
                } // 2nd_if
                else if (s[i] == min_count)
                    min[i]=1;
            } // 1st_if
        } //1st_for
        printf("The least appearing characters are: ");
        for (i=0; i<256; i++) {
            if (min[i])
                putchar(i);
        } //2nd_for
    }