Files
OI-source/2.136.cpp
2023-08-03 09:22:52 +08:00

34 lines
502 B
C++

#include<iostream>
#include<vector>
#include<queue>
#include<set>
using namespace std;
typedef long long LL;
const int coeff[3]={2,3,5};
int main()
{
priority_queue<LL,vector<LL>,greater<LL> > q;
set<LL> s;
q.push(1);
s.insert(1);
for(int i=1;;i++)
{
LL x=q.top();q.pop();
if(i==1500)
{
cout<<"The 1500'th ugly number is "<<x<<"."<<endl;
return 0;
}
for(int j=0;j<3;j++)
{
LL x2=x*coeff[j];
if(!s.count(x2))
{
s.insert(x2);
q.push(x2);
}
}
}
return 0;
}