Uva202 - Repeating Decimals

#include<stdio.h>
#include<string.h>
int fraction[4000];
int mod[4000];
int main(){
int a, b;
int q,p,len;
int d = 0;
while (scanf("%d%d", &a, &b) != EOF){
mod[0] = a;
fraction[0] = a / b;
for (q = 1;; q++){
mod[q] = (mod[q - 1] - b*fraction[q - 1]) * 10;
fraction[q] = mod[q] / b;
for ( p = 1;p<q; p++){
if (mod[p] == mod[q]){
len = q - p;
d = 1; break;
}
}
if (d) break;
}
printf("%d/%d = %d.", a, b, fraction[0]);
for (int i = 1; i < p; i++){
printf("%d", fraction[i]);
}
printf("(");
for (int i = p; i < q; i++){
if (i >50){
printf("...");
break;
}
printf("%d", fraction[i]);
}
printf(")\n   %d = number of digits in repeating cycle\n\n", len);
d = 0;
}
return 0;
}