摘要： Spiral Matrix II问题：Given an integern, generate a square matrix filled with elements from 1 ton2in spiral order.思路： 矩阵的旋转常用模板我的代码1：public class Soluti... 阅读全文

摘要： Symmetric Tree问题：Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).思路： dfs我的代码：public class Solution { ... 阅读全文

摘要： Rotate Image问题：You are given annxn2D matrix representing an image.Rotate the image by 90 degrees (clockwise).Follow up:Could you do this in-place?思路：　... 阅读全文

摘要： Minimum Path Sum问题：Given amxngrid filled with non-negative numbers, find a path from top left to bottom right whichminimizesthe sum of all numbers alo... 阅读全文

摘要： Populating Next Right Pointers in Each Node II问题：Populate each next pointer to point to its next right node. If there is no next right node, the next ... 阅读全文

摘要： Permutations问题：Given a collection of numbers, return all possible permutations.For example,[1,2,3]have the following permutations:[1,2,3],[1,3,2],[2,1... 阅读全文

摘要： Balanced Binary Tree问题：Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary ... 阅读全文

摘要： Best Time to Buy and Sell Stock问题：Say you have an array for which theithelement is the price of a given stock on dayi.If you were only permitted to co... 阅读全文

摘要： Swap Nodes in Pairs问题：Given a linked list, swap every two adjacent nodes and return its head.For example,Given1->2->3->4, you should return the list a... 阅读全文

摘要： Remove Element问题：Given an array and a value, remove all instances of that value in place and return the new length.The order of elements can be change... 阅读全文