最短路问题(Shortest Path Problem)是图论中一个经典的问题,旨在找到从一个顶点到另一个顶点的最短路径。 所给定的图可以是有向图(directed graph)也可以是无向图(undirected graph),并且边可以有权重(weights),即每条边有一个数值表示从一个顶点到另一个顶点的距离或成本。 最短路问题的常见变种包括: 单源最短...
[宽度优先搜索] leetcode 864 Shortest Path to Get All Keys problem:https://leetcode.com/problems/shortest-path-to-get-all-keys/ 这道题其它地方都挺基础的,就是普通的宽搜,难点主要在于visit状态的维护。 如果不考虑visit数组,则会出现大量重复的来回搜索,比如刚刚从1->2,下一步又从2->1。 但是,已...
LeetCode 1091. Shortest Path in Binary Matrix二进制矩阵中的最短路径【Medium】【Python】【BFS】 Problem LeetCode In an N by N square grid, each cell is either empty (0) or blocked (1). Aclear path from top-left to bottom-righthas lengthkif and only if it is composed of cellsC_1, ...
多源最短路问题(Multi-Source Shortest Path Problem,MSSP)是图论中的一个经典问题,它的目标是在给定图中找到从多个源点到所有其他顶点的最短路径。这个问题可以视为单源最短路问题(Single-Source Shortest Path Problem, SSSP)的扩展。 什么是单源最短路问题呢?其实我们上次讲的就可以归结在单元最短路问题当中,其实...
It’s a dynamic programming problem the shortest path to position (i,j) comes from two position:the shortest path to (i,j-1)+ grid[i][j] the shortest path to (i-1,j)+ grid[i][j]class Solution { public: int minPathSum(vector<vector<int>>& grid) { int n = grid[0].size(...
Can you solve this real interview question? Shortest Path in a Grid with Obstacles Elimination - You are given an m x n integer matrix grid where each cell is either 0 (empty) or 1 (obstacle). You can move up, down, left, or right from and to an empty ce
Dutch National Flag Problem (medium) 3. Pattern: Fast & Slow pointers, 快慢指针类型 这种模式,有一个非常出门的名字,叫龟兔赛跑。咱们肯定都知道龟兔赛跑啦。但还是再解释一下快慢指针:这种算法的两个指针的在数组上(或是链表上,序列上)的移动速度不一样。还别说,这种方法在解决有环的链表和数组时特...
Given ann x nbinary matrixgrid, returnthe length of the shortestclear pathin the matrix. If there is no clear path, return-1. Aclear pathin a binary matrix is a path from thetop-leftcell (i.e.,(0, 0)) to thebottom-rightcell (i.e.,(n - 1, n - 1)) such that: ...
Leetcode 218 The Skyline Problem Leetcode 480. Sliding Window Median (这个题用TreeMap超级方便) Leetcode 318 Count of Smaller Numbers After Self (这个题线段树、二分索引树、TreeMap都可以) 动态规划(Dynamic Programming) 基础知识:这里指的是用for循环方式的动态规划,非Memoization Search方式。DP可以在多...
For the purpose of this problem, we define empty string as valid palindrome. 【解答】注意大小写,注意数字和字母都要算有效字符。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 public class Solution { public boolean isPalindrome(String s) { int left = 0; int right = s.length()-1; whil...