Ugly Numbers UVA - 136
作者:互联网
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, 15, ...
shows the first 11 ugly numbers. By convention, 1 is included.
Write a program to find and print the 1500’th ugly number.
Input
There is no input to this program.
Output
Output should consist of a single line as shown below, with ‘<number>’ replaced by the number computed.
Sample Output
The 1500'th ugly number is *<*number*>*.
HINT
使用set来存储副本,判断是否已经存储过。
Accepted
#include<iostream>
#include<set>
#include<queue>
#include<vector>
using namespace std;
typedef long long LL;
const int coeff[3] = { 2,3,5 };
int main()
{
priority_queue<LL, vector<LL>, greater<LL> >pq;
set<LL>s;
pq.push(1);s.insert(1);
for (int i = 1;;i++) {
LL x = pq.top();pq.pop();
if (i == 1500) {
cout << "The 1500'th ugly number is " << x << "." << endl;
break;
}
for (int j = 0;j < 3;j++) {
LL x2 = x * coeff[j];
if (!s.count(x2)) { s.insert(x2);pq.push(x2); }
}
}
}
标签:pq,int,number,Ugly,1500,136,include,numbers,Numbers 来源: https://www.cnblogs.com/3236676588buladuo/p/14350182.html