#include <bits/stdc++.h>
using namespace std;
int n;
struct node
{
int xi;
int yi;
};
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> n;
node a[n];
for(int i = 1; i <= n; i++)
{
cin >> a[i].xi >> a[i].yi;
}
double ans = 0;
for(int i = 1; i <= n; i++)
{
for(int j = i + 1; j <= n; j++)
{
for(int k = j + 1; k <= n; k++)
{
if(i != j && j != k && i != k)
{
int temp = max(a[i].xi,max(a[j].xi,a[k].xi));
int tempppp = max(a[i].yi,max(a[j].yi,a[k].yi));
int tempp = min(a[i].xi,min(a[j].xi,a[k].xi));
int temppp = min(a[i].yi,min(a[j].yi,a[k].yi));
ans += ((temp - tempp) * 1.0) * ((tempppp - temppp) * 1.0) / 2;
}
}
}
}
printf("%.1lf",ans);
return 0;
}
WA + TLE求调
