HDU 1014 Uniform Generator

#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
int seed[100001];
int main()
{
    int s,m;
    while(scanf("%d%d",&s,&m) != EOF){
        bool flag = true;
         seed[0] = 0;
         for(int i=1; i<m; i++){
            seed[i] = (seed[i-1]+s)%m;
        }
        //排序
        sort(seed, seed+m);
        for(int i=0; i<m; i++){
                if(seed[i] != i){
                    flag = false;
                    break;
                }
        }
        if(flag){
             printf("%10d%10d    Good Choice\n\n", s, m);
        }else{
            printf("%10d%10d    Bad Choice\n\n", s, m);
            }
    }
 return 0;
}