原题链接 假设只有一个政党,那么这题就退化成求树的直径的问题了,所以我们可以从此联想至\(k\)个政党的情况. 先处理出每个政党的最大深度,然后枚举每个政党的其它点,通过\(LCA\)计算长度取\(\max\)即可. 因为枚举只是枚举该政党的所有点,所以总的枚举复杂度依旧是\(O(n)\),总复杂度\(O(nlog_2n)\). #include<cstdio> #include<cmath> using namespace std; const int N = 2e5 + 10;…
P2971 [USACO10HOL]牛的政治Cow Politics 农夫约翰的奶牛住在N (2 <= N <= 200,000)片不同的草地上,标号为1到N.恰好有N-1条单位长度的双向道路,用各种各样的方法连接这些草地.而且从每片草地出发都可以抵达其他所有草地.也就是说,这些草地和道路构成了一种叫做树的图.输入包含一个详细的草地的集合,详细说明了每个草地的父节点P_i (0 <= P_i <= N).根节点的P_i == 0, 表示它没有父节点.因为奶牛建立了1到K一共K (1…
农夫约翰的奶牛住在N ( <= N <= ,)片不同的草地上,标号为1到N.恰好有N-1条单位长度的双向道路,用各种各样的方法连接这些草地.而且从每片草地出发都可以抵达其他所有草地.也就是说,这些草地和道路构成了一种叫做树的图.输入包含一个详细的草地的集合,详细说明了每个草地的父节点P_i ( <= P_i <= N).根节点的P_i == , 表示它没有父节点.因为奶牛建立了1到K一共K ( <= K <= N/)个政党.每只奶牛都要加入某一个政党,其中, 第i只奶牛…
P3080 [USACO13MAR]牛跑The Cow Run 题目描述 Farmer John has forgotten to repair a hole in the fence on his farm, and his N cows (1 <= N <= 1,000) have escaped and gone on a rampage! Each minute a cow is outside the fence, she causes one dollar worth of dam…
P2853 [USACO06DEC]牛的野餐Cow Picnic 题目描述 The cows are having a picnic! Each of Farmer John's K (1 ≤ K ≤ 100) cows is grazing in one of N (1 ≤ N ≤ 1,000) pastures, conveniently numbered 1...N. The pastures are connected by M (1 ≤ M ≤ 10,000) one-way path…
P2853 [USACO06DEC]牛的野餐Cow Picnic 题目描述 The cows are having a picnic! Each of Farmer John's K (1 ≤ K ≤ 100) cows is grazing in one of N (1 ≤ N ≤ 1,000) pastures, conveniently numbered 1...N. The pastures are connected by M (1 ≤ M ≤ 10,000) one-way path…
题目描述 Farmer John's cows are living on \(N (2 \leq N \leq 200,000)\)different pastures conveniently numbered \(1..N\). Exactly \(N-1\) bidirectional cow paths (of unit length) connect these pastures in various ways, and each pasture is reachable from…
题目描述 The cows are having a picnic! Each of Farmer John's K (1 ≤ K ≤ 100) cows is grazing in one of N (1 ≤ N ≤ 1,000) pastures, conveniently numbered 1...N. The pastures are connected by M (1 ≤ M ≤ 10,000) one-way paths (no path connects a pasture to…
https://www.luogu.org/problem/show?pid=3029 题目描述 Farmer John has hired a professional photographer to take a picture of some of his cows. Since FJ's cows represent a variety of different breeds, he would like the photo to contain at least one cow fro…
题目描述 Like everyone else, FJ is always thinking up ways to increase his revenue. To this end, he has set up a series of tolls that the cows will pay when they traverse the cowpaths throughout the farm. The cows move from any of the N (1 <= N <= 250)…