2257: [Jsoi2009]瓶子和燃料

#include<cstdio>
#include<map>
#include<cmath>
using namespace std;
map<int, int>ss;

void fun(int num){
    for (int i = 1; i <= sqrt(num); ++i){
        if (num%i == 0){
            ss[i]++;
            if (i != num / i)ss[num / i]++;
        }
    }
}

int main(){
    int n, m, x;
    while (scanf("%d%d", &n, &m) != EOF){
        while (n--){
            scanf("%d", &x);    fun(x);
        }
        map<int, int>::iterator it = ss.end();
        ss[0] = 0;
        for (--it; it != ss.begin(); --it){
        //    printf("%d -- %d\n", it->first, it->second);
            if (it->second >= m){
                printf("%d\n", it->first);  break;
            }
        }
        ss.clear();
    }
}