已知正方形两对角线坐标,求另外两个点坐标
https://zhidao.baidu.com/question/374490574378994124.html
例题 https://www.luogu.com.cn/problem/P1959
https://www.luogu.com.cn/problem/P2867
https://zhidao.baidu.com/question/374490574378994124.html
例题 https://www.luogu.com.cn/problem/P1959
https://www.luogu.com.cn/problem/P2867