poj3253

利用priority_queue模拟霍夫曼树。注意结果要用long long.

#include <cstdio>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <queue>
usingnamespace std;

struct Integer
{
    longlong x;
    Integer(longlong xx):x(xx)
    {}
};

booloperator< (const Integer &a, const Integer &b)
{
    return a.x > b.x;
}

int main()
{
    //freopen("D:\\t.txt", "r", stdin);
int n;
    scanf("%d", &n);
    priority_queue<Integer> pq;
    for (int i =0; i < n; i++)
    {
        int a;
        scanf("%d", &a);
        pq.push(Integer(a));
    }
    longlong ans =0;
    while (1)
    {
        Integer sum(0), sum2(0);
        sum = pq.top();
        pq.pop();
        if (pq.empty())
            break;
        sum2 = pq.top();
        pq.pop();
        pq.push(Integer(sum.x + sum2.x));
        ans += sum.x + sum2.x;
    }
    printf("%I64d\n", ans);
    return0;
}