hdu 3199 Hamming Problem

#include <iostream>
#include <cstdio>
#include <queue>
#include <limits>
using namespace std;

typedef long long ll;
typedef pair<ll,int> node_type;
ll result;

int main(){
    //cout<<(numeric_limits<long long>::max)()<<endl;
    ll p1,p2,p3,n;
    while(~scanf("%lld%lld%lld%lld",&p1,&p2,&p3,&n)){
        priority_queue<node_type,vector<node_type>,greater<node_type> > q;
        q.push(make_pair(1,p1));
        for(int i = 1; i <= n+1; i++){
            node_type node  = q.top();
            q.pop();
            if(node.second == p1){
                q.push(make_pair(node.first*p1,p1));
                q.push(make_pair(node.first*p2,p2));
                q.push(make_pair(node.first*p3,p3));
            }
            else if(node.second == p2){
                q.push(make_pair(node.first*p2,p2));
                q.push(make_pair(node.first*p3,p3));
            }
            else
                q.push(make_pair(node.first*p3,p3));
            result = node.first;
        }
        printf("%lld\n",result);
    }
    return 0;
}