poj3253

小根堆

#include <iostream>
#include <stdio.h>
#define M 20002
using namespace std;
int A[M],len;
void Min_Heap(int i)
{
	int l=i<<1,r=l+1;
	int temp,least=i;
	if(l<=len&&A[l]<A[i])
	{
		least=l;
	}
	if(r<=len&&A[r]<A[least])
	{
		least=r;
	}
	if(least<=len&&least!=i)
	{
		temp=A[i];A[i]=A[least];A[least]=temp;
		Min_Heap(least);
	}
}
void Build_Min_Heap()
{
	for (int i=len/2;i>=1;i--)
	{
		Min_Heap(i);
	}
}
void Min_Sort()
{
	int temp;
	Build_Min_Heap();
	while(len>=2)
	{
		temp=A[1];A[1]=A[len];A[len]=temp;
		len--;
		Min_Heap(1);
	}
}
int main()
{
	int i,n,j;
	__int64 t,sum=0;
	scanf("%d",&n);
	len=n;
	for (i=1;i<=n;i++)
	{
		scanf("%d",&A[i]);
	}
	Min_Sort();
	for (i=n;i>=2;i--)
	{
		t=A[i]+A[i-1];
		j=i-2;
		while(j>=1&&t>A[j])
		{
			A[j+1]=A[j];j--;
		}
		A[j+1]=t;
		sum+=t;
	}
	printf("%I64d\n",sum);
	return 0;
}