CF1929D Sasha and a Walk in the City 题解】的更多相关文章

3125: CITY Time Limit: 10 Sec  Memory Limit: 128 MBSubmit: 486  Solved: 213[Submit][Status][Discuss] Description 小明和小华要参加NOI,踏上了去X市的火车. 小明望着窗外的田野,大楼,工厂缓缓后退,在思考着什么. 这时,对面的小华拿出手机对着他说:“看!我们在这个位置!” 小明望着手机上显示的地图,城市被接到分割成各个方块,而自己所在的点在慢慢移动. 他突然意识到自己甚至还没游历过这…
这个题目大意是: 有N个城市,编号为0~N-1,给定N-1条无向带权边,Q个询问,每个询问求三个城市连起来的最小权值. 多组数据 每组数据  1 < N < 50000  1 < Q < 70000: 一道多源最短路的题目,注意题目数据:N.Q都很大 不能考虑Floyd.SPFA.Dijkstra.Bellman-Ford等最短路算法 再看N-1条边,明显构成一棵树,最短路有且只有一条 很明显需要LCA.... 不懂LCA的点!我!点!我! 我们所熟知的LCA是求两个点的最短路,而…
Okabe and City 题解: 将行和列也视为一个点. 然后从普通的点走到行/列的点的话,就代表这行/列已经被点亮了. 然后将费用为0的点建上边. 注意讨论(n,m)非亮的情况下. 代码: #include<bits/stdc++.h> using namespace std; #define Fopen freopen("_in.txt","r",stdin); freopen("_out.txt","w"…
第二节课从最简单的模型开始入手:七桥问题. 首先,先去wikipedia上了解一些有关七桥问题的背景知识.http://en.wikipedia.org/wiki/Seven_Bridges_of_K%C3%B6nigsberg 而这节课要做的事情,其实在wiki上已经有所介绍,建模分两步: 1. 将地图分隔开的部分染成四种颜色,并且标记桥: 2. 再将其抽象成node和edge...…
D. Bear and Two Paths time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Bearland has n cities, numbered 1 through n. Cities are connected via bidirectional roads. Each road connects two dist…
D. Bear and Two Paths time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Bearland has n cities, numbered 1 through n. Cities are connected via bidirectional roads. Each road connects two dist…
D. Bear and Two Paths 题目连接: http://www.codeforces.com/contest/673/problem/D Description Bearland has n cities, numbered 1 through n. Cities are connected via bidirectional roads. Each road connects two distinct cities. No two roads connect the same p…
D. Bear and Two Paths time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Bearland has n cities, numbered 1 through n. Cities are connected via bidirectional roads. Each road connects two dist…
题目链接: D. Bear and Two Paths time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Bearland has n cities, numbered 1 through n. Cities are connected via bidirectional roads. Each road connects tw…
Benches Time Limit:500MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Description The city park of IT City contains n east to west paths and n north to south paths. Each east to west path crosses each north to south path,…