題解

題目大意 n和d 還有m個點的x y座標 問座標是否在(0, d) (d, 0) (n-d, n) (n, n-d)四個點圍城的矩形內

判斷矩形不好判斷 可以判斷是否在四個角的三角形內 不包括邊上

AC程式碼

#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const int INF = 0x3f3f3f3f;

int main()
{
#ifdef LOCAL
	freopen("C:/input.txt", "r", stdin);
#endif
 

	int n, m, d;
	cin >> n >> d >> m;
	for (int i = 0; i < m; i++)
	{
		int x, y, xx, yy;
		cin >> x >> y;
		int flag = 1;
		xx = x, yy = y;
		if (xx + yy < d)
			flag = 0;
		xx = n - x, yy = y;
		if (xx + yy < n - d)
			flag = 0;
		xx = n - x, yy = n - y;
		if (xx +
 
 yy < d)
			flag = 0;
		xx = x, yy = n - y;
		if (xx + yy < n - d)
			flag = 0;
		if (flag)
			cout << "YES" << endl;
		else
			cout << "NO" << endl;
	}

	return 0;
}