HOJ 1008 How many n

http://acm.hit.edu.cn/judge/show.php?Proid=1008

 

 

#include <cstdio>#include <cstring>const int MAX = 10240;const int ELE[] = { 2, 4, 5, 8, 10 };int main(){bool visited[MAX];int i, a, b; while(scanf("%d %d", &a, &b) != EOF) { bool quick = false; for(i = 0; i < 5; i++) if(b % ELE[i] == 0 && a % ELE[i] != 0) { quick = true; break; } if(quick) { printf("0/n"); continue; }int n = 0;memset(visited, false, sizeof(visited));for(i = 1; true; i++) {n = (10*n+a) % b;if(n == 0) { printf("%d/n", i); break; }else if(visited[n] || i >= b) { printf("0/n"); break; }else visited[n] = true;}}return 0;}