POJ 3253 Fence Repair 优先队列

#include<stdio.h>
#include<iostream>
#include<queue>
/*
* 使用longlong保存结果
* 优先队列解决问题
* 哈夫曼树
*/
using namespace std;
priority_queue<int, vector<int>, greater<int> > pq;
int a[20005];
int main()
{
int n;
cin>>n;
for(int i= 0 ; i < n ; i++)
{
scanf("%d",&a[i]);
pq.push(a[i]);
}
long long anss = 0;
int ans = pq.top();
pq.pop();
ans += pq.top();
pq.pop();
anss += ans;
while(!pq.empty())
{
pq.push(ans);
ans = pq.top();
pq.pop();
ans += pq.top();
pq.pop();
anss+=ans;
}
cout<<anss;

}

#include<stdio.h>
#include<iostream>
#include<queue>
/*
* 结构体类型优先队列直接通过friend关键字重载小于号
*/
using namespace std;
struct node
{
friend bool operator < (node n1,node n2)
{
return n1.priority < n2.priority;
}
int priority;
int value;
};
priority_queue <node> qn;//必须要重载运算符
int main()
{
int i;
node b[10];
b[0].priority = 6; b[0].value = 1;
b[1].priority = 9; b[1].value = 5;
b[2].priority = 2; b[2].value = 3;
b[3].priority = 8; b[3].value = 2;
b[4].priority = 1; b[4].value = 4;
for(i = 0; i < 5; i++)
qn.push(b[i]);
for(i = 0; i < 5; i++)
{
cout<<qn.top().priority<<'\t'<<qn.top().value<<endl;
qn.pop();
}
}