15pts,老规矩闭关

#include<bits/stdc++.h>
using namespace std;
struct Students{
	int x;
	int y;
};
bool cmp(Students a,Students b){
	if(a.x!=b.x) return a.x>b.x;
	if(a.y!=b.y) return a.y>b.y;
}
Students s[3005];
int main(){
	int n,cnt=0;
	cin>>n;
	for(int i=1;i<=n;i++) cin>>s[i].x>>s[i].y;
	for(int i=n;i>1;i--){
		for(int j=1;j<i;j++){
			if(cmp(s[i],s[i+1])==false){
				swap(s[i],s[i+1]);
				++cnt;
			}
		}
	}
	cout<<cnt;
}