Travel The country frog lives in has nn towns which are conveniently numbered by 1,2,…,n. Among n(n−1) / 2 pairs of towns, m of them are connected by bidirectional highway, which needs aa minutes to travel. The other pairs are connected by railway, w…

The Best Travel Design Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 1359   Accepted: 340 Description Dou Nai is an excellent ACM programmer, and he felt so tired recently that he wants to release himself from the hard work. He plans a…

1030 Travel Plan (30)(30 分) A traveler's map gives the distances between cities along the highways, together with the cost of each highway. Now you are supposed to write a program to help a traveler to decide the shortest path between his/her startin…

有趣的思考题 Description Input * 第一行: 两个空格分开的数, N和M * 第2..M+1行: 三个空格分开的数a_i, b_i,和t_i Output * 第1..N-1行: 第i行包含一个数:从牛棚_1到牛棚_i+1并且避免从牛棚1到牛棚i+1最短路经上最后一条牛路的最少的时间.如果这样的路经不存在,输出-1. 题目分析 做法一 暴力树剖线段树 做法二 并查集[bzoj1576] [Usaco2009 Jan]安全路经Travel #include<bits/stdc++…

POJ 1511 Invitation Cards / UVA 721 Invitation Cards / SPOJ Invitation / UVAlive Invitation Cards / SCU 1132 Invitation Cards / ZOJ 2008 Invitation Cards / HDU 1535 (图论,最短路径) Description In the age of television, not many people attend theater perfor…

POJ 2387 Til the Cows Come Home (图论,最短路径) Description Bessie is out in the field and wants to get back to the barn to get as much sleep as possible before Farmer John wakes her for the morning milking. Bessie needs her beauty sleep, so she wants to g…

目录 1 问题描述 2 解决方案   1 问题描述 1310 One-way traffic In a certain town there are n intersections connected by two- and one-way streets. The town is very modern so a lot of streets run through tunnels or viaducts. Of course it is possible to travel between…

图论是NOIP的一个非常重要的考点,换句话说,没有图论,NOIP的考纲就得少一大半(虽然很NOIP没有考纲) 图论这玩意吧,和数论一样是非常变态的东西,知识点又多又杂,但是好在一个事,他比较直观比较好想 图 对于一张图而言,我们定义图是一种由边和点构成的的一个玩意(其实是严谨定义我记不住了QWQ,但是不影响学习) 一般来说,图的存储难度主要在记录边的信息 无向图的存储中,只需要将一条无向边拆成两条即可 邻接矩阵:用一个二维数组 edg[N][N] 表示 edg[i][j] 就对应由 i 到 j…

图论 学好图论的基础: 必须意识到图论hendanteng xuehuifangqi(雾 图 G = (V,E) 一般来说,图的存储难度主要在记录边的信息 无向图的存储中,只需要将一条无向边拆成两条即可 存图: 1.邻接矩阵(经典):代码连接 用一个二维数组 edg[N][N] 表示 edg[i][j] 就对应由 i 到 j 的边信息 edg[i][j] 可以记录 Bool,也可以记录边权 举个栗子: 0 0 1 0 0 0 1 1 1 1 0 1 0 1 1 0 首先这是个无向图(因为它是对称…

图论的常见题目有两类,一类是求两点间最短距离,另一类是拓扑排序,两种写起来都很烦. 求最短路径: 127. Word Ladder Given two words (beginWord and endWord), and a dictionary's word list, find the length of shortest transformation sequence from beginWord to endWord, such that: Only one letter can be…