Ugly Numbers(set,queue,vector) -uva 136

Ugly Numbers

Time Limit: 1000ms

Memory Limit: 10000KB

This problem will be judged on PKU. Original ID: 1338
64-bit integer IO format: %lld      Java class name: Main

Ugly numbers are numbers whose only prime factors are 2, 3 or 5. The sequence 
1, 2, 3, 4, 5, 6, 8, 9, 10, 12, ... 
shows the first 10 ugly numbers. By convention, 1 is included. 
Given the integer n,write a program to find and print the n'th ugly number. 

Input

Each line of the input contains a postisive integer n (n <= 1500).Input is terminated by a line with n=0.

Output

For each line, output the n’th ugly number .:Don’t deal with the line with n=0.

Sample Input

1290

Sample Output

1210

Source

New Zealand 1990 Division I,UVA 136

#include<iostream>#include<queue>#include<set>#include<vector>using namespace std; typedef long long LL;int a[3]={2,3,5};int main(){priority_queue<LL,vector<LL>,greater<LL> > pq;set<LL> st;pq.push(1);st.insert(1);for(int i=1;;i++){LL x=pq.top();pq.pop();if(i==1500) cout<<x<<endl;for(int j=0;j<3;j++){if(!st.count(a[j]*x)) {st.insert(a[j]*x);pq.push(a[j]*x);}}}}