BFS

[LeetCode] 752. Open the Lock (Daily Question)

문제 You have a lock in front of you with 4 circular wheels. Each wheel has 10 slots: '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'. The wheels can rotate freely and wrap around: for example we can turn '9' to be '0', or '0' to be '9'. Each move consists of turning one wheel one slot. The lock initially starts at '0000', a string representing the state of the 4 wheels. You are given a list of d..

[LeetCode] 200. Number of Islands (Daily Question)

문제 Given an m x n 2D binary grid grid which represents a map of '1's (land) and '0's (water), return the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by water. 바다를 의미하는 0과 섬의 땅을 의미하는 1로 구성된 2차원 배열 grid가 주어졌을 때, 섬 해안선의 길이를 구하는 문제이다. Example 1: Input: grid =[ [..