题解：B4253 [科大国创杯小学组 2024] 几何

#include<bits/stdc++.h>
#define int long long
#define inf 0x7f7f7f7f
using namespace std;
const int maxn = 1e6 + 100;
inline int read() {
	int x=0,f=1;char ch=getchar();
	while (ch<'0'||ch>'9'){if (ch=='-') f=-1;ch=getchar();}
	while (ch>='0'&&ch<='9'){x=x*10+ch-48;ch=getchar();}
	return x*f;
}
int ans1 , ans2 , ans3 = inf , ans4 = inf , x[maxn] , y[maxn] , ans , n , opt;//ans1维护x-y的最大值，ans2维护x+y的最大值，ans3维护x-y的最小值，ans4维护x+y的最大值
signed main() {
	n = read();
	opt = read();
	for(int i = 1; i <= n; i++) x[i] = read() , y[i] = read() , ans1 = max(ans1 , x[i] - y[i]) , ans2 = max(ans2 , x[i] + y[i]) , ans3 = min(ans3 , x[i] - y[i]) , ans4 = min(ans4 , x[i] + y[i]);
	if(opt == 1) {//暴力枚举
		for(int i = 1; i <= n; i++) {
			for(int j = 1; j <= n; j++) {
				int dx = x[i] - x[j] , dy = y[i] - y[j];
				ans = max(ans , dx * dx + dy * dy);
			}
		}
		cout << ans << endl;
	}else cout << max(ans1 - ans3 , ans2 - ans4) << endl;//数学公式
	return 0;
}