Shortest Path  Accepts: 40  Submissions: 610  Time Limit: 4000/2000 MS (Java/Others)  Memory Limit: 131072/131072 K (Java/Others) Problem Description There is a path graph G=(V,E)G=(V,E) with nn vertices. Vertices are numbered from 11 to nn and there…

题目链接:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=1760 Given a weighted directed graph, we define the shortest path as the path who has the smallest length among all the path connecting the source vertex to the target vertex. And if two…

How Many Shortest Path 标签: 网络流 描述 Given a weighted directed graph, we define the shortest path as the path who has the smallest length among all the path connecting the source vertex to the target vertex. And if two path is said to be non-overlapping…

人老了就比较懒,故意挑了到看起来很和蔼的题目做,然后套个spfa和dinic的模板WA了5发,人老了,可能不适合这种刺激的竞技运动了…… 题目链接:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=2760 Description Given a weighted directed graph, we define the shortest path as the path who has the smallest leng…

Description Given a weighted directed graph, we define the shortest path as the path who has the smallest length among all the path connecting the source vertex to the target vertex. And if two path is said to be non-overlapping, it means that the tw…

题目传送门 题目描述:给出一颗树,每条边都有权值,然后列出一个n的全排列,对于所有的全排列,比如1 2 3 4这样一个排列,要算出1到2的树上距离加2到3的树上距离加3到4的树上距离,这个和就是一个排列的val,计算所有全排列的val和就可以了. 思路:对于一个n的全排列,会发现 任意x-y的边在这个全排列中出现的次数是一样的,(x-y和y到x是不一样的边).也就是说我只需要计算出这个次数,然后再乘以所有边的总和(所有x-y和y-x的和)就可以了. 次数就是 ,(边的总数除以边的种类)化简一下就…

How Many Shortest Path 题目: 给出一张图,求解最短路有几条.处理特别BT.还有就是要特别处理map[i][i] = 0,数据有不等于0的情况! 竟然脑残到了些错floyd! !.!! ! 14次wrong.! !..! .. 算法: 先最短路处理,把在最短路上的边加入上.既是.dist[s][i] + map[i][j] == dist[s][j]表示从起点到i点加上当前边是最短路.把这个加入到网络流边集中.容量为1.然后,建立一个超级源点.容量为INF. #includ…

Shortest Path Problem? You are given an undirected graph with weighted edges. The length of some path between two vertices is the bitwise xor of weights of all edges belonging to this path (if some edge is traversed more than once, then it is include…

这两道都用到了线段树分治和按秩合并可撤销并查集. Shortest Path Queries 给出一个连通带权无向图,边有边权,要求支持 q 个操作: x y d 在原图中加入一条 x 到 y 权值为 d 的边 x y 把图中 x 到 y 的边删掉 x y 表示询问 x 到 y 的异或最短路 保证任意操作后原图连通无重边自环且操作均合法 n,m,q≤200000 题解 与WC2011 最大XOR和路径一样,先考虑没有加边删边的做法 做出原图的任意一棵生成树 把每个非树边和树边形成的环丢进线性基里…

题目链接 Given a m * n grid, where each cell is either 0 (empty) or 1 (obstacle). In one step, you can move up, down, left or right from and to an empty cell. Return the minimum number of steps to walk from the upper left corner (0, 0) to the lower right…