C++ :

#include<iostream>
using namespace std;

int sum = 0;

int main()
{
	int N;
	cin >> N;
	int *num = new int[N];
	for(int i = 0; i < N; i++)
	{
		cin >> num[i];
	}
	int min = 0;
	int min_d = 0;
	int min_mid = 0;
	int min_dmid = 0;
	for(int count = N; count > 1; count--)
	{
		min_mid = 0;
		min_dmid = 0;
		for(int i = 0; i < N; i++)
		{
			if((num[i] != 0) && (num[i] < num[min]))
			{
				min = i;
			} 
		}
		//令mid_d为不等于min的一个值，排除num[min]后求剩下的元素最小值 
		for(int i = 0; i < N; i++)
		{
			if((num[i] != 0) && (i != min)) 
			{
				min_d = i;
				break; 
			}
		}
		for(int i = 0; i < N; i++)
		{
			if(i == min) continue;
			else
			{
				if((num[i] != 0) && (num[i] < num[min_d]))
				{
					min_d = i;
				}
			}
		} 
		min_dmid = num[min_d];//因为相加后就得将改坐标删除，所以用两个中间变量记录两个最小值 
		min_mid = num[min];
		for(int i = 0; i < N; i++)
		{
			if((num[i] != 0) && (num[i] == min_dmid))
			{
				sum += min_dmid;
				num[i] = 0;
			}
			if((num[i] != 0) && (num[i] == min_mid) && (min_mid != min_dmid))
			{
				sum += min_mid;
				num[i] = 0;
			}
		}
		num[min] = min_mid + min_dmid;
	}
	cout << sum << endl;
	delete [] num;
	return 0;
}