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原创刷题-Valid Sudoku 缺python

Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.The Sudoku board could be partially filled, where empty cells are filled with the character '.'.A partially fille

2014-12-05 16:12:28 264

原创刷题-Min Stack 缺python

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.push(x) -- Push element x onto stack.pop() -- Removes the element on top of the stack.top() -- Get

2014-12-05 16:11:31 341

原创刷题-Symmetric Tree 缺python

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 / \ 2 2 / \ / \3 4 4 3But the f

2014-12-05 16:10:45 300

原创刷题-Same Tree 缺python

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.java：/

2014-12-05 16:10:03 347

原创刷题-Valid Parentheses 缺python

Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.The brackets must close in the correct order, "()" and "()[]{}" are all va

2014-12-05 16:09:18 292

原创刷题-Path Sum 缺python

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

2014-12-05 16:07:59 279

原创刷题-Minimum Depth of Binary Tree 缺python

Given a binary tree, find its minimum depth.The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.java：/** * Definition for bi

2014-12-05 16:06:58 379

原创刷题-Pascal's Triangle II 缺python

Given an index k, return the kth row of the Pascal's triangle.For example, given k = 3,Return [1,3,3,1].Note:Could you optimize your algorithm to use only O(k) extra space?java：publi

2014-12-05 16:05:46 236

原创刷题-Pascal's Triangle 缺python

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], [1,4,6,4,1]]java：public class Soluti

2014-12-05 16:05:06 315

原创刷题-Valid Palindrome 缺python

Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a plan, a canal: Panama" is a palindrome."race a car" is not a

2014-12-05 16:03:40 216

原创刷题-Roman to Integer 缺python

Given a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.public class Solution { public int romanToInt(String s) { if (s.length

2014-12-05 16:02:39 270

原创刷题-String to Integer (atoi)缺python

Implement atoi to convert a string to an integer.Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input ca

2014-12-05 16:01:30 388

原创刷题-ZigZag Conversion 缺python

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)P A H NA P L S I

2014-12-05 14:34:32 278

原创刷题—Palindrome Number

Determine whether an integer is a palindrome. Do this without extra space.java:通过int转换为string，看string是否首位与相应的位相等，判断是不是palindromepublic class Solution { public boolean isPalindrome(int x) {

2014-12-05 11:42:26 212

原创刷题-Count and Say-缺python

The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ...1 is read off as "one 1" or 11.11 is read off as "two 1s" or 21.21 is read off as

2014-12-04 18:00:56 212

原创刷题-Maximum Depth of Binary Tree

java解法：public class Solution { public int maxDepth(TreeNode root) { if (root==null) return 0; int left = maxDepth(root.left); int right = maxDepth(root.right);

2014-12-04 17:07:41 485

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