这题暴力还是能过呀

#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
#define MAXN 100100
#define x first
#define y second
#define int long long
typedef pair<int,int> PII;
PII a[MAXN];
signed main(){
	int n;
	scanf("%lld",&n);
	for(int i=1;i<=n;i++){
		int c,d;
		cin>>c>>d;
		a[i]={d,c};
	}
	int ans=0;
	sort(a+1,a+1+n);
	for(int i=1;i<=n;i++)
	for(int j=i+1;j<=n;j++)
	ans+=max(a[i].y,a[j].y)*(a[j].x-a[i].x);
	printf("%lld",ans);
	return 0;
}