[AtCoder-AT_ABC108_B]题解(C++)

Part I Preface

原题目(Luogu)
原题目(AtCoder)

Part II Sketch

Part III Analysis

观察这道题，我们很容易想到，必须推导出 \(x1, y1, x2, y2\) 与 \(x3, y3, x4, y4\) 之间的关系。
我们观察下图。

可以发现：
\(\begin{aligned}\begin{cases}x3 = x2 - (y2 - y1)\\ y3 = y2 + (x2 - x1)\\x4 = x3 - (x2 - x1)\\y4 = y3 - (y2 - y1)\end{cases}\end{aligned}\)

套公式计算即可。

Part IV Code

#include <iostream>
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
int x1, x2, y1, y2;
int x3, x4, y3, y4;
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> x1 >> y1 >> x2 >> y2;
    x3 = x2 - (y2 - y1);
    y3 = y2 + (x2 - x1);
    x4 = x3 - (x2 - x1);
    y4 = y3 - (y2 - y1);
    cout << x3 << " " << y3 << " " << x4 << " " << y4;
    return 0;
}

Part V Record

Record