leetcode.com 2023-06-16
🔴1569.number-of-ways-to-reorder-array-to-get-same-bst
🏷️ Tags
#tree #union_find #binary_search_tree #memoization #array #math #divide_and_conquer #dynamic_programming #binary_tree #combinatorics
🔴1569.number-of-ways-to-reorder-array-to-get-same-bst
🏷️ Tags
#tree #union_find #binary_search_tree #memoization #array #math #divide_and_conquer #dynamic_programming #binary_tree #combinatorics
Telegraph
number-of-ways-to-reorder-array-to-get-same-bst
Given an array nums that represents a permutation of integers from 1 to n. We are going to construct a binary search tree (BST) by inserting the elements of nums in order into an initially empty BST. Find the number of different ways to reorder nums so that…
leetcode.cn 2023-06-18
🟡1254.number-of-closed-islands
🏷️ Tags
#depth_first_search #breadth_first_search #union_find #array #matrix
🟡1254.number-of-closed-islands
🏷️ Tags
#depth_first_search #breadth_first_search #union_find #array #matrix
Telegraph
number-of-closed-islands
二维矩阵 grid 由 0 （土地）和 1 （水）组成。岛是由最大的4个方向连通的 0 组成的群，封闭岛是一个 完全 由1包围（左、上、右、下）的岛。 请返回 封闭岛屿 的数目。 示例 1： 输入：grid = [[1,1,1,1,1,1,1,0],[1,0,0,0,0,1,1,0],[1,0,1,0,1,1,1,0],[1,0,0,0,0,1,0,1],[1,1,1,1,1,1,1,0]] 输出：2 解释： 灰色区域的岛屿是封闭岛屿，因为这座岛屿完全被水域包围（即被 1 区域包围）。 示例 2： 输入：grid…