poj 3253 哈夫曼树

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#define MAX 20010

using namespace std;

long long  Q[MAX];
long long  Index;
long long  Cost;

int cmp(const void *a,const void *b)
{
    return *(int *)b - *(int *)a;
}

void Insert(long long  temp)
{
    if(Index < 2) return;
    for(int i = Index - 2;i >= 0;i--){
        if(temp > Q[i])
         Q[i+1] = Q[i];
        else
        {
            Q[i+1] = temp;
            return;
        }
    }
    Q[0] = temp;
}

int main()
{
    int n;
    cin>>n;
    Cost = 0;
    Index = n;

    for(int i = 0;i < n;i++)
     cin>>Q[i];

    qsort(Q,Index,sizeof(long long),cmp);

    while(Index > 1){

        long long temp = Q[Index-1] + Q[Index-2];
        Cost += temp;
        Index--;
        Insert(temp);
    }

    cout<<Cost<<endl;

    return 0;
}