题解：P13752 【MX-X17-T1】Walk,Walk,Walk

weifengzhaomi · 2025-08-17 17:57:23 · 题解

思路

容易发现，对于任意一条线如果在两个点的中间，就一定会经过这条直线，所以我们把每条线记录下来，判断一下。

代码

#include<bits/stdc++.h>
using namespace std;
int a,b,a1,b1,n,ans,x[100010],y[100010];
int main(){
    cin >> n;
    for (int i = 1;i <= n;i++) scanf("%d%d",&x[i],&y[i]);
    cin >> a >> b >> a1 >> b1;
    for (int i = 1;i <= n;i++){
        if (x[i] == 1){
            if ((y[i] >= a && y[i] <= a1) || (y[i] <= a && y[i] >= a1)) ans++;
        } else if ((y[i] >= b && y[i] <= b1) || (y[i] <= b && y[i] >= b1)) ans++;
    }
    cout << ans << endl;
}