摘要：According to the Wikipedia's article: "The Game of Life, also known simply as Life, is a cellular automaton devised by the British mathematician John Horton Conway in 1970." Given a board with m by n... 阅读全文

摘要：An undirected, connected tree with N nodes labelled 0...N-1 and N-1 edges are given. The ith edge connects nodes edges[i][0] and edges[i][1] together. 阅读全文

摘要：Given a robot cleaner in a room modeled as a grid. Each cell in the grid can be empty or blocked. The robot cleaner with 4 given APIs can move forward, turn left or turn right. Each turn it made is... 阅读全文

摘要：Given an 2D board, count how many battleships are in it. The battleships are represented with 'X's, empty slots are represented with '.'s. You may assume the following rules: * You receive a valid bo... 阅读全文

摘要：Let's play the minesweeper game (Wikipedia, online game)! You are given a 2D char matrix representing the game board. 'M' represents an unrevealed min 阅读全文

摘要：Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surro... 阅读全文

摘要：A group of friends went on holiday and sometimes lent each other money. For example, Alice paid for Bill's lunch for $10. Then later Chris gave Alice $5 for a taxi ride. We can model each transactio... 阅读全文

摘要：Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surro... 阅读全文

摘要：Approach #2: Depth-First Search [Accepted] Intuition As in Approach #1, the crux of the problem is whether you reach a cycle or not. Let us perform a 阅读全文

摘要：There are N students in a class. Some of them are friends, while some are not. Their friendship is transitive in nature. For example, if A is a direct friend of B, and B is a direct friend of C, then... 阅读全文

摘要：Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assum... 阅读全文

摘要：https://leetcode.com/problems/24-game/solution/ You have 4 cards each containing a number from 1 to 9. You need to judge whether they could operated through *, /, +, -, (, ) to get the value of 24. E... 阅读全文

摘要：Example 2: 阅读全文

摘要：737. Sentence Similarity II Given two sentences words1, words2 (each represented as an array of strings), and a list of similar word pairs pairs, determine if two sentences are similar. For example... 阅读全文

摘要：399. Evaluate Division Equations are given in the format A / B = k, where A and B are variables represented as strings, and k is a real number (floating point number). Given some queries, return th... 阅读全文

摘要：In this problem, a tree is an undirected graph that is connected and has no cycles. The given input is a graph that started as a tree with N nodes (wi 阅读全文

摘要：Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected 阅读全文

摘要：valid tree: no cycle, one connected component Given n nodes labeled from 0 to n-1 and a list of undirected edges (each edge is a pair of nodes), write 阅读全文