Implement next permutation, which rearranges numbers into the lexicographically next greater permutatio…

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题目： Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For exa…

题目： Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a nu…

题目： Given two binary strings, return their sum (also a binary string). For example, a = "11" b = "1"…

Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path f…

这是悦乐书的第217次更新，第230篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第85题（顺位题号是404）。找到给定二叉树中所有左叶的总和。例如： 二叉树中有两个左叶，分别为9和15。 …

前言 个人网站 公众号: 北京程序猿, 网站 : https://yaml.vip 算法题 题干 给定一个二叉搜索树和一个目标结果，如果 BST 中存在两个元素且它们的和等于给定的目标结果，则返回 true。 示例 输入…

1.0 问题描述 实现数据结构：堆。 2.0 问题分析 堆一般使用数组来表示，其中某个节点下标i的两个子节点的下标为 2i+1 和 2i+2。堆是一棵完全二叉树。 堆有3种基本操作：创建，插入，删除。 这3种操作都需要通…