为什么要写半平面交啊
#include<cstdio>
#include<algorithm>
#define maxn 105
#define inf 0x3f3f3f3f
using namespace std;

int n,x[maxn],y[maxn],mnx,mxx,mny,mxy;

int main(){
	int cas = 0;
	while(~scanf("%d",&n) && n){
		for(int i=0;i<n;i++) scanf("%d%d",&x[i],&y[i]);
		mnx = mny = -inf;
		mxx = mxy = inf;
		for(int i=0;i<n;i++){
			int v = (i+1)%n;
			if(x[i] == x[v]){
				if(y[i] > y[v]) mxx = min(mxx , x[i]);
				else mnx = max(mnx , x[i]);
			}
			else{
				if(x[i] < x[v]) mxy = min(mxy , y[i]);
				else mny = max(mny , y[i]);
			}
		}
		printf("Floor #%d\n",++cas);
		if(mnx > mxx || mny > mxy) puts("Surveillance is impossible.");
		else puts("Surveillance is possible.");
		putchar('\n');
	}
}

• 好家伙 (22) QuantumBolt 2021-07-13 23:47:53
• 虽然不知道为什么你的代码就过了， 但是之前有人发的数据明显能把你hack掉， 数据如下 (117) QuantumBolt 2021-07-14 00:12:29