POJ 3253 Fence Repair【哈夫曼树】

哈夫曼树

注意结果要用long long 因为Li可能被加和多次 N*max(Li)不不是求和的最大值

#include <iostream>
#include <queue>
#include <vector>
#include <algorithm>

using namespace std;

#define debug(x) cout<<#x<<": "<<(x)<<endl;
#pragma warning(disable:4996)



int main()
{
    //freopen("../in2.txt","r",stdin);

    priority_queue< int, vector<int>, greater<int> > q;
    int N;
    cin >> N;
    for (int i = 0; i < N; ++i) {
        int t;
        cin >> t;
        q.push(t);
    }
    long long int ret = 0;
    while (q.size() > 1) {
        int a = q.top();
        q.pop();
        int b = q.top();
        q.pop();
        q.push(a + b);
        ret += a + b;
    }
    
    cout << ret << endl;
    
    return 0;
}