摘要：
A robot is located at the top-left corner of amxngrid (marked 'Start' in the diagram below).The robot can only move either down or right at any point ... 阅读全文
摘要：
Given a binary tree, return thepostordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3return[3,2,1].题解... 阅读全文
摘要：
Givennpairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, givenn= 3, a solution set is:"((()))... 阅读全文
摘要：
Given an array withnobjects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, wh... 阅读全文
摘要：
GivennumRows, generate the firstnumRowsof Pascal's triangle.For example, givennumRows= 5,Return[ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1]... 阅读全文
摘要：
The gray code is a binary numeral system where two successive values differ in only one bit.Given a non-negative integernrepresenting the total number... 阅读全文
摘要：
Given two sorted integer arrays A and B, merge B into A as one sorted array.Note:You may assume that A has enough space (size that is greater or equal... 阅读全文
摘要：
Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric: 1 / \ ... 阅读全文
摘要：
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... 阅读全文
摘要：
You are climbing a stair case. It takesnsteps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb... 阅读全文