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;

}