给你二叉树的根节点 root 和一个表示目标和的整数 targetSum .判断该树中是否存在 根节点到叶子节点 的路径,这条路径上所有节点值相加等于目标和 targetSum .如果存在,返回 true :否则,返回 false . 叶子节点 是指没有子节点的节点. 来源:力扣(LeetCode)链接:https://leetcode-cn.com/problems/path-sum著作权归领扣网络所有.商业转载请联系官方授权,非商业转载请注明出处. 答案: /** * Definition…

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…

A. Shortest path of the king 题目连接: http://www.codeforces.com/contest/3/problem/A Description The king is left alone on the chessboard. In spite of this loneliness, he doesn't lose heart, because he has business of national importance. For example, he…

今天cf又杯具的只写出2题, 虽然AB题20分钟左右就搞定了, 但是CD写了2个小时也没写出来 D题我用到了DFS, 虽然必不正确, 但是我至少发现了一个问题, 那就是我连DFS都忘了, 于是怒找DFS板子写一写... 题面见https://www.luogu.com.cn/problem/P1605 /* * Author: RoccoShi * Time: 2020-06-08 02:08:41 */ #include <bits/stdc++.h> using namespace std…

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…

Kuro is living in a country called Uberland, consisting of nn towns, numbered from 11to nn, and n−1n−1 bidirectional roads connecting these towns. It is possible to reach each town from any other. Each road connects two towns aa and bb. Kuro loves wa…

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…

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…