还可以用指针++
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include<string.h>
#include <algorithm>
#include <queue>
using namespace std;
#define ll long long
priority_queue<ll,vector<ll>,greater<ll> > pi;
int main( )
{
//freopen("in.txt","r",stdin);
int i,j,before,zero,n,k,p2,p3,p5;
ll a[1501],temp;
p2=p3=p5=1;
a[1]=1;j=1;
pi.push(1);before=0;
while( j<= 1500 )
{
temp=pi.top();
pi.pop();
if(temp!=before)
{
a[j++]=temp;
pi.push(temp*2);
pi.push(temp*3);
pi.push(temp*5);
before=temp;
}
}
while(scanf("%d",&n)!=EOF)
printf("%lld\n",a[n]);
return 0;
}