Two Paths Time Limit: 2000MS   Memory Limit: 65536KB   64bit IO Format: %I64d & %I64u Submit Status Description As you know, Bob's brother lives in Flatland. In Flatland there are n cities, connected by n - 1 two-way roads. The cities are numbered…

题意: N个点构成一棵树.树枝的长度都是1. 在当中找两条不相交[没有公共点]的路,使得二者长度之积最大. (2 ≤ n ≤ 200) 思路: 一开始思路好麻烦,好麻烦,好麻烦,,,,,,,而且WA,,,,, 正解: 必定存在第三条路径连接两条最长路径.[因为是一棵树]. 去掉第三条路径上的某根树枝就可以将原树分成两个区域了,两条最长路径分别在一个区域里. 然后分别求两个区域的直径,相乘. N不大,枚举. 代码: int const N=210; int n; vector<int> G[N]…

#include<bits/stdc++.h> using namespace std; #define maxn 300 ]; int n,head[maxn],tot,a,b,dis[maxn]; void init(){ memset(head,-,sizeof head); tot=; } void addedge(int u,int v){ edge[tot].from=u,edge[tot].to=v;edge[tot].nxt=head[u];head[u]=tot++; edg…

题目链接: http://codeforces.com/contest/14/problem/D D. Two Paths time limit per test2 secondsmemory limit per test64 megabytes 问题描述 As you know, Bob's brother lives in Flatland. In Flatland there are n cities, connected by n - 1 two-way roads. The citie…

题目链接:点击打开链接 题意:给定一棵树 找2条点不反复的路径,使得两路径的长度乘积最大 思路: 1.为了保证点不反复,在图中删去一条边,枚举这条删边 2.这样得到了2个树,在各自的树中找最长链.即树的直径,然后相乘就可以 #include<stdio.h> #include<iostream> #include<string.h> #include<set> #include<vector> #include<map> #inclu…

给出一棵树,找出两条不相交即没有公共点的路径,使得两个路径的长度的乘积最大. 思路:枚举树中的边,将该边去掉,分成两棵树,分别求出这两棵树的直径,乘起来维护一个最大值即可. #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> using namespace std; + ; int n; struct Edge { int u, v, nxt; bool…

tiyi:给你n个节点和n-1条边(无环),求在这个图中找到 两条路径,两路径不相交,求能找的两条路径的长度的乘积最大值: #include <iostream> #include <cstdio> #include <cstring> #include <cstdlib> #include <cmath> #include <vector> #include <queue> #include <stack>…

H. Capital City[ Color: Black ]Bahosain has become the president of Byteland, he is doing his best to make people's liveseasier. Now, he is working on improving road networks between the cities.If two cities are strongly connected, people can use BFS…

传送门 Park Visit Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3721    Accepted Submission(s): 1667 Problem Description Claire and her little friend, ykwd, are travelling in Shevchenko's Park! T…

D. Two Paths time limit per test 2 seconds memory limit per test 64 megabytes input standard input output standard output As you know, Bob's brother lives in Flatland. In Flatland there are n cities, connected by n - 1 two-way roads. The cities are n…