HachiLin的博客

1. 难度：简单 104：二叉树的最大深度 题目描述 给定一个二叉树，找出其最大深度。二叉树的深度为根节点到最远叶子节点的最长路径上的节点数。 说明: 叶子节点是指没有子节点的节点。 例子 给定二叉树 [3,9,20,null,null,15,7]    3   /   \  9    20    /   \    15   7 返回它的最大深度3 ...

Description Given an array and a value, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the i...

Description You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numb...

Description Follow up for “Remove Duplicates”: What if duplicates are allowed at most twice? For example: Given sorted array nums = [1,1,1,2,2,3], Your function should return lengt...

Description Given a sorted array, remove the duplicates in-place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do t...

Description Given numRows, generate the first numRows of Pascal’s triangle. For example, given numRows = 5,Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4...

Description Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array. Note: You may assume that nums1 has enough space (size that is greater or equal to m ...