12 2014 档案
摘要：Binary Search Tree IteratorImplement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST.Callin...
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摘要：Missing RangesGiven a sorted integer array where the range of elements are [lower, upper] inclusive, return its missing ranges.For example, given [0, ...
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摘要：Exercise:Vectorization习题的链接：Exercise:Vectorization注意点：MNIST图片的像素点已经经过归一化。如果再使用Exercise:Sparse Autoencoder中的sampleIMAGES.m进行归一化，将使得训练得到的可视化权值如下图：更改trai...
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摘要：Exercise:Sparse Autoencoder习题的链接：Exercise:Sparse Autoencoder注意点：1、训练样本像素值需要归一化。因为输出层的激活函数是logistic函数，值域(0,1)，如果训练样本每个像素点没有进行归一化，那将无法进行自编码。2、训练阶段，向量化实现...
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摘要：（一）Autoencoders and Sparsity章节公式错误：s2 应为 s3。意为从第2层（隐藏层）i节点到输出层j节点的误差加权和。（二）Support functions for loading MNIST in Matlab文件名错误% Change the filenames if...
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摘要：Factorial Trailing ZeroesGiven an integern, return the number of trailing zeroes inn!.Note:Your solution should be in logarithmic time complexity.Cred...
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摘要：Binary Tree Upside DownGiven a binary tree where all the right nodes are either leaf nodes with a sibling (a left node that shares the same parent nod...
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摘要：Excel Sheet Column NumberRelated to questionExcel Sheet Column TitleGiven a column title as appear in an Excel sheet, return its corresponding column ...
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摘要：Longest Substring with At Most Two Distinct CharactersGiven a string, find the length of the longest substring T that contains at most 2 distinct char...
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摘要：1、相同点：回溯法在实现上也是遵循深度优先的，即一步一步往前探索，而不像广度优先那样，由近及远一片一片地扫。2、不同点（1）访问序深度优先遍历： 目的是“遍历”，本质是无序的。也就是说访问次序不重要，重要的是都被访问过了。可以参见题Surrounded Regions，深度优先只需要把从边界起始的...
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摘要：1、使用结构体grid作为map的keystruct grid{ int x; int y;};（1）需要自定义比较函数operator &,const std::deque &)”: 未能从“const grid”为“const std::deque &”推导 模板 参数（2）需要定义...
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摘要：Median of Two Sorted ArraysThere are two sorted arrays A and B of size m and n respectively. Find the median of the two sorted arrays. The overall run...
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摘要：Longest Substring Without Repeating CharactersGiven a string, find the length of the longest substring without repeating characters. For example, the ...
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摘要：Add Two NumbersYou are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes co...
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摘要：Longest Palindromic SubstringGiven a stringS, find the longest palindromic substring inS. You may assume that the maximum length ofSis 1000, and there...
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摘要：ZigZag ConversionThe string"PAYPALISHIRING"is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern i...
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摘要：String to Integer (atoi)Implementatoito convert a string to an integer.Hint:Carefully consider all possible input cases. If you want a challenge, plea...
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摘要：Majority ElementGiven an array of sizen, find the majority element. The majority element is the element that appears more than⌊ n/2 ⌋times.You may ass...
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摘要：Palindrome NumberDetermine whether an integer is a palindrome. Do this without extra space.click to show spoilers.Some hints:Could negative integers b...
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摘要：Regular Expression MatchingImplement regular expression matching with support for'.'and'*'.'.' Matches any single character.'*' Matches zero or more o...
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摘要：Container With Most WaterGivennnon-negative integersa1,a2, ...,an, where each represents a point at coordinate (i,ai).nvertical lines are drawn such t...
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摘要：Integer to RomanGiven an integer, convert it to a roman numeral.Input is guaranteed to be within the range from 1 to 3999.逐区间做处理。解法一：非递归class Solution...
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摘要：Roman to IntegerGiven a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.解法一：非递归从左到右遍历每个字符，并记录上个字符来处理...
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摘要：3Sum ClosestGiven an arraySofnintegers, find three integers inSsuch that the sum is closest to a given number, target. Return the sum of the three int...
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摘要：4SumGiven an arraySofnintegers, are there elementsa,b,c, anddinSsuch thata+b+c+d= target? Find all unique quadruplets in the array which gives the sum...
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摘要：Excel Sheet Column TitleGiven a non-zero positive integer, return its corresponding column title as appear in an Excel sheet.For example: 1 -> A ...
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摘要：Letter Combinations of a Phone NumberGiven a digit string, return all possible letter combinations that the number could represent.A mapping of digit ...
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摘要：Valid ParenthesesGiven a string containing just the characters'(',')','{','}','['and']', determine if the input string is valid.The brackets must clos...
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摘要：Generate ParenthesesGivennpairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, givenn= 3, a sol...
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摘要：Merge k Sorted ListsMergeksorted linked lists and return it as one sorted list. Analyze and describe its complexity.多路归并。1、用make_heap函数维护一个大小为k的最小堆。注：...
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摘要：Swap Nodes in PairsGiven a linked list, swap every two adjacent nodes and return its head.For example,Given1->2->3->4, you should return the list as2-...
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摘要：Reverse Nodes in k-GroupGiven a linked list, reverse the nodes of a linked listkat a time and return its modified list.If the number of nodes is not a...
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摘要：Divide Two IntegersDivide two integers without using multiplication, division and mod operator.If it is overflow, return MAX_INT.不能用乘法，我们可以移位啊，移p位就相当于...
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摘要：Substring with Concatenation of All WordsYou are given a string,S, and a list of words,L, that are all of the same length. Find all starting indices o...
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摘要：Next PermutationImplement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.If such arrangemen...
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摘要：Longest Valid ParenthesesGiven a string containing just the characters'('and')', find the length of the longest valid (well-formed) parentheses substr...
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摘要：1、局部静态变量(1)生存期：存储在静态数据区，本模块运行结束不会销毁，程序结束时才销毁。(2)初始化：当且仅当本模块初次运行时初始化。2、外部静态变量/静态函数限制全局变量的作用域为本文件。3、静态数据成员/成员函数表示该成员/成员函数属于此类，不依附与具体对象。常用于生成对象的计数器。
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摘要：形式：在成员函数后面加上const限定词，表示不会修改对象内容。例如Circle类：class Circle{ double r;public: Circle(double newr) { r = newr; } double get_r() const ...
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摘要：Search for a RangeGiven a sorted array of integers, find the starting and ending position of a given target value.Your algorithm's runtime complexity ...
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摘要：Valid SudokuDetermine if a Sudoku is valid, according to:Sudoku Puzzles - The Rules.The Sudoku board could be partially filled, where empty cells are ...
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摘要：Fraction to Recurring DecimalGiven two integers representing the numerator and denominator of a fraction, return the fraction in string format.If the ...
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摘要：Count and SayThe count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ...1is read off as"one 1"or11.11is r...
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摘要：Combination Sum IIGiven a collection of candidate numbers (C) and a target number (T), find all unique combinations inCwhere the candidate numbers sum...
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摘要：First Missing PositiveGiven an unsorted integer array, find the first missing positive integer.For example,Given[1,2,0]return3,and[3,4,-1,1]return2.Yo...
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摘要：Trapping Rain WaterGivennnon-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to tr...
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摘要：Maximum GapGiven an unsorted array, find the maximum difference between the successive elements in its sorted form.Try to solve it in linear time/spac...
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摘要：Multiply StringsGiven two numbers represented as strings, return multiplication of the numbers as a string.Note: The numbers can be arbitrarily large ...
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摘要：Wildcard MatchingImplement wildcard pattern matching with support for'?'and'*'.'?' Matches any single character.'*' Matches any sequence of characters...
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摘要：区分const出现在*前还是*后前：例如const int *p，这种表示情况下，p本身可以改变，即p可以指向不同的地址，但是p指向的内容不可改变。就像你喜欢看书，图书馆规定你可以任意借阅及更换书本，但是你不能涂改书中的内容。后：例如int* const p，这种表示情况下，p指向地址不能改变，但是...
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摘要：Permutations IIGiven a collection of numbers that might contain duplicates, return all possible unique permutations.For example,[1,1,2]have the follow...
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摘要：PermutationsGiven a collection of numbers, return all possible permutations.For example,[1,2,3]have the following permutations:[1,2,3],[1,3,2],[2,1,3]...
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摘要：AnagramsGiven an array of strings, return all groups of strings that are anagrams.Note: All inputs will be in lower-case.首先解释一下什么是anagrams：在不考虑顺序的情况下，...
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摘要：Pow(x, n)Implement pow(x,n).按照定义做的O(n)肯定是TLE的。利用这个信息：x2n = (xn)2有个注意点，当n为负是，直接取反是不可行的。由于int的表示范围是[2-31, 231-1]，当n为INT_MIN时，取反会溢出。因此需要对n==INT_MIN单独考虑。另...
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摘要：N-Queens IIFollow up for N-Queens problem.Now, instead outputting board configurations, return the total number of distinct solutions.简单的回溯法。cur[i] ==...
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摘要：Merge IntervalsGiven a collection of intervals, merge all overlapping intervals.For example,Given[1,3],[2,6],[8,10],[15,18],return[1,6],[8,10],[15,18]...
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摘要：Insert IntervalGiven a set ofnon-overlappingintervals, insert a new interval into the intervals (merge if necessary).You may assume that the intervals...
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摘要：Length of Last WordGiven a stringsconsists of upper/lower-case alphabets and empty space characters' ', return the length of last word in the string.I...
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摘要：Spiral Matrix IIGiven an integern, generate a square matrix filled with elements from 1 ton2in spiral order.For example,Givenn=3,You should return the...
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摘要：Spiral MatrixGiven a matrix ofmxnelements (mrows,ncolumns), return all elements of the matrix in spiral order.For example,Given the following matrix:[...
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摘要：给定正整数n，求1,2,3,...,n的全排列解法一：递归，结果并不为字母序排列。void Helper(vector v, int low, int high){ if(low == high) { for(int i = 0; i v(n,0); for(int...
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摘要：Permutation SequenceThe set[1,2,3,…,n]contains a total ofn! unique permutations.By listing and labeling all of the permutations in order,We get the fo...
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摘要：Rotate ListGiven a list, rotate the list to the right bykplaces, wherekis non-negative.For example:Given1->2->3->4->5->NULLandk=2,return4->5->1->2->3-...
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摘要：Unique Paths IIFollow up for "Unique Paths":Now consider if some obstacles are added to the grids. How many unique paths would there be?An obstacle an...
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摘要：Unique PathsA 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 a...
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摘要：Merge Two Sorted ListsMerge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the fir...
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摘要：Add BinaryGiven two binary strings, return their sum (also a binary string).For example,a ="11"b ="1"Return"100".先进行对齐操作，然后从右往左逐位相加，注意进位即可。class Solut...
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摘要：Valid NumberValidate if a given string is numeric.Some examples:"0"=>true" 0.1 "=>true"abc"=>false"1 a"=>false"2e10"=>trueNote:It is intended for the ...
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摘要：Plus OneGiven a non-negative number represented as an array of digits, plus one to the number.The digits are stored such that the most significant dig...
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摘要：Text JustificationGiven an array of words and a lengthL, format the text such that each line has exactlyLcharacters and is fully (left and right) just...
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摘要：Sqrt(x)Implementint sqrt(int x).Compute and return the square root ofx.解法一：牛顿迭代法求n的平方根，即求f(x)=x2-n的零点设初始值为x0，注，不要设为0，以免出现除数为0，见后。则过(x0,f(x0))点的切线为g(x)...
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摘要：Edit DistanceGiven two wordsword1andword2, find the minimum number of steps required to convertword1toword2. (each operation is counted as 1 step.)You...
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摘要：Set Matrix ZeroesGiven amxnmatrix, if an element is 0, set its entire row and column to 0. Do it in place.click to show follow up.Follow up:Did you us...
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摘要：Minimum Window SubstringGiven a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n).Fo...
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摘要：1、计数排序如果给定上下界，并且区间不大的话，最适用。比如对于英文字母数组进行排序。时间复杂度O(n)，空间复杂度O(n)void countSort(int A[], int n, int low, int high){ int size = high-low+1; vector co...
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摘要：CombinationsGiven two integersnandk, return all possible combinations ofknumbers out of 1 ...n.For example,Ifn= 4 andk= 2, a solution is:[ [2,4], [3...
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摘要：Search in Rotated Sorted Array IIFollow up for "Search in Rotated Sorted Array":What ifduplicatesare allowed?Would this affect the run-time complexity...
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摘要：Search in Rotated Sorted ArraySuppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e.,0 1 2 4 5 6 7might become4 5 6 7 0 1 2)....
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摘要：Remove Duplicates from Sorted ListGiven a sorted linked list, delete all duplicates such that each element appear onlyonce.For example,Given1->1->2, r...
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摘要：Remove Duplicates from Sorted List IIGiven a sorted linked list, delete all nodes that have duplicate numbers, leaving onlydistinctnumbers from the or...
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摘要：Maximal RectangleGiven a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area.如果用DP来做，判断(begin...
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摘要：Largest Rectangle in HistogramGivennnon-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of l...
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摘要：Scramble StringGiven a strings1, we may represent it as a binary tree by partitioning it to two non-empty substrings recursively.Below is one possible...
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摘要：Find Peak ElementA peak element is an element that is greater than its neighbors.Given an input array wherenum[i] ≠ num[i+1], find a peak element and ...
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摘要：Gray CodeThe gray code is a binary numeral system where two successive values differ in only one bit.Given a non-negative integernrepresenting the tot...
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摘要：SubsetsGiven a set of distinct integers,S, return all possible subsets.Note:Elements in a subset must be in non-descending order.The solution set must...
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摘要：Subsets IIGiven a collection of integers that might contain duplicates,S, return all possible subsets.Note:Elements in a subset must be in non-descend...
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摘要：Reverse Linked List IIReverse a linked list from positionmton. Do it in-place and in one-pass.For example:Given1->2->3->4->5->NULL,m= 2 andn= 4,return...
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摘要：Binary Tree Inorder TraversalGiven a binary tree, return theinordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ ...
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摘要：Unique Binary Search Trees IIGivenn, generate all structurally uniqueBST's(binary search trees) that store values 1...n.For example,Givenn= 3, your pr...
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摘要：Unique Binary Search TreesGivenn, how many structurally uniqueBST's(binary search trees) that store values 1...n?For example,Givenn= 3, there are a to...
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摘要：Interleaving StringGivens1,s2,s3, find whethers3is formed by the interleaving ofs1ands2.For example,Given:s1="aabcc",s2="dbbca",Whens3="aadbbcbcac", r...
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摘要：Validate Binary Search TreeGiven a binary tree, determine if it is a valid binary search tree (BST).Assume a BST is defined as follows:The left subtre...
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摘要：Recover Binary Search TreeTwo elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Note:A sol...
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摘要：Same TreeGiven two binary trees, write a function to check if they are equal or not.Two binary trees are considered equal if they are structurally ide...
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摘要：Symmetric TreeGiven a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric...
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