金组题什么的都要绕个弯才能AC..不想银组套模板= = 题目大意:给n个点,求最小边长使得此正方形内的点数不少于c个 首先一看题就知道要二分边长len 本来打算用二维前缀和来判断,显然时间会爆,而且坐标最大10000是不可行的 为保证效率,检验的时间应该在O(n2) 所以我们先给x排个序,以每个点的x坐标为左边界,x+len-1为右边界 然后以y为关键字从小到大序后枚举点,用双指针法O(n)更新len以内能保存多少个点 点数大于等于c就可行 #include<stdio.h> #include…

[BZOJ1720][Usaco2006 Jan]Corral the Cows 奶牛围栏 Description Farmer John wishes to build a corral for his cows. Being finicky beasts, they demand that the corral be square and that the corral contain at least C (1 <= C <= 500) clover fields for afterno…

我对二分的理解:https://www.cnblogs.com/AKMer/p/9737477.html 题目传送门:https://www.lydsy.com/JudgeOnline/problem.php?id=1720 坐标值域很大,但是真正涉及的只有\(500\)个,我们可以离散化做.二分长度,直接二维前缀和检查就行了 h时间复杂度:\(O(log10000*n^2*logn)\) 空间复杂度:\(O(n)\) 代码如下: #include <cstdio> #include <…

http://www.lydsy.com/JudgeOnline/problem.php?id=1720 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 177  Solved: 90[Submit][Status][Discuss] Description Farmer John wishes to build a corral for his cows. Being finicky beasts, they demand that the corr…

1654: [Usaco2006 Jan]The Cow Prom 奶牛舞会 Time Limit: 5 Sec  Memory Limit: 64 MB Description The N (2 <= N <= 10,000) cows are so excited: it's prom night! They are dressed in their finest gowns, complete with corsages and new shoes. They know that ton…

Description The N (2 <= N <= 10,000) cows are so excited: it's prom night! They are dressed in their finest gowns, complete with corsages and new shoes. They know that tonight they will each try to perform the Round Dance. Only cows can perform the…

Description The N (2 <= N <= 10,000) cows are so excited: it's prom night! They are dressed in their finest gowns, complete with corsages and new shoes. They know that tonight they will each try to perform the Round Dance. Only cows can perform the…

Description The N (2 <= N <= 10,000) cows are so excited: it's prom night! They are dressed in their finest gowns, complete with corsages and new shoes. They know that tonight they will each try to perform the Round Dance. Only cows can perform the…

http://www.lydsy.com/JudgeOnline/problem.php?id=1654 请不要被这句话误导..“ 如果两只成功跳圆舞的奶牛有绳索相连,那她们可以同属一个组合．” 这句话没啥用.. #include <cstdio> #include <cstring> #include <cmath> #include <string> #include <iostream> #include <algorithm>…

Description 约翰的N(2≤N≤10000)只奶牛非常兴奋,因为这是舞会之夜!她们穿上礼服和新鞋子,别上鲜花,她们要表演圆舞．     只有奶牛才能表演这种圆舞．圆舞需要一些绳索和一个圆形的水池．奶牛们围在池边站好,顺时针顺序由1到N编号．每只奶牛都面对水池,这样她就能看到其他的每一只奶牛．为了跳这种圆舞,她们找了M(2≤M≤50000)条绳索．若干只奶牛的蹄上握着绳索的一端,绳索沿顺时针方绕过水池,另一端则捆在另一些奶牛身上．这样,一些奶牛就可以牵引另一些奶牛．有的奶牛可能握有很多绳…