poj 2231 Moo Volume

#include<iostream>
#include<string.h>
#include<math.h>
#include<fstream>
#include<algorithm>
#include<stdio.h>
#include<queue>
#include<vector>
#define MAXSIZE 100
using namespace std;
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))
typedef long long int ll;
int  N = 0;
ll dat[10010];
ll ans = 0;
int main()
{
//freopen("data_2231.txt","r",stdin);
while(scanf("%d", &N) != EOF)
{
ans = 0;
for (int i = 0; i < N; i++)
{
scanf("%lld", &dat[i]);
}
sort (dat, dat + N);
for (int i = 0; i < N; i++)
{
for (int j = 0; j < i; j++)
{
ans += (long)abs ((long)(dat[j] - dat[i]));
}
}
printf("%lld\n", 2 * ans);
}

return 0;
}