Given an unsorted array nums, reorder it such that nums[0] < nums[1] > nums[2] < nums[3].... Example 1: Input: nums = [1, 5, 1, 1, 6, 4] Output: One possible answer is [1, 4, 1, 5, 1, 6]. Example 2: Input: nums = [1, 3, 2, 2, 3, 1] Output: One po…

本博客是个人原创的针对leetcode上的problem的解法,所有solution都基本通过了leetcode的官方Judging,个别未通过的例外情况会在相应部分作特别说明. 欢迎互相交流! email: tomqianmaple@gmail.com 后续更多的easy题已经不属于Top Interview Questions,所以现在就不集中精力去做了,只做到目前的100题左右. Palindrome Linked List Lowest Common Ancestor of a Bina…

# 增强学习成果 有一个研究成果,在学习中传授他人知识和讨论是最高效的做法,而看书则是最低效的做法(具体研究成果没找到地址).我写LeetCode博客主要目的是增强学习成果.当然,我也想出名,然而不知道能否出名. # 给算法的新手们提供一种思考方式的参考 提前说明,本人也不是高手. 算法这个东西有点玄乎.很多新手(包括我)初期入门的时候都学的是<算法导论>,然而我并不觉得<算法导论>是一本学习算法很好的书. 我们设计算法的流程,并不是像<算法导论>那样,好像天生就知道这…

终于将LeetCode的免费题刷完了,真是漫长的第一遍啊,估计很多题都忘的差不多了,这次开个题目汇总贴,并附上每道题目的解题连接,方便之后查阅吧~ 477 Total Hamming Distance 44.10% Meidum 475 Heaters  30.20% Easy 474 Ones and Zeroes  34.90% Meidum 473 Matchsticks to Square  31.80% Medium 472 Concatenated Words 29.20% Hard…

Find the length of the longest substring T of a given string (consists of lowercase letters only) such that every character in T appears no less than k times. Example 1: Input: s = "aaabb", k = 3 Output: 3 The longest substring is "aaa"…

题目链接:Path Sum II | LeetCode OJ Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2],…

题目链接:Path Sum | LeetCode OJ Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11…

题目链接:Balanced Binary Tree | LeetCode OJ Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more tha…

题目链接:Same Tree | LeetCode OJ Given two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if they are structurally identical and the nodes have the same value. Tags: Depth-first Search 分析 很基本的一道深度优…

题目链接:Recover Binary Search Tree | LeetCode OJ Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Note: A solution using O(n) space is pretty straight forward. Could you devise a constan…