HDU 5690 All X 暴力循环节

分析：暴力找循环节就好了

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <string>
#include <stack>
#include <vector>
#include <map>
#include <queue>
#include <algorithm>
#include <utility>
using namespace std;
typedef long long LL;
const int N=1e4+5;
const int INF=0x3f3f3f3f;
const LL mod=1e9+7;
bool vis[N];
int cur[N*2];
int main()
{
    int T,cas=0;
    scanf("%d",&T);
    while(T--){
      LL x,m,k,c;
      scanf("%I64d%I64d%I64d%I64d",&x,&m,&k,&c);
      LL t=0,cnt=1;
      bool flag=0;
      memset(vis,0,sizeof(vis));
      for(;;++cnt){
        t=t*10+x;
        if(vis[t%k]){flag=1;break;}
        vis[t%k]=1;cur[cnt]=t%k;
        t%=k;
      }
      if(flag){m%=cnt;if(m==0)m=cnt;}
      printf("Case #%d:
",++cas);
      if(cur[m]==c)printf("Yes
");
      else printf("No
");
    }
    return 0;
}