摘要：Flatten Binary Tree to Linked ListGiven a binary tree, flatten it to a linked list in-place.For example,Given 1 / \ 2 5 / \ \ 3 4 6The flattened tree should look like: 1 \ 2 \ 3 \ 4 \ 5 \ ...
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摘要：Populating Next Right Pointers in Each Node IIFollow up for problem "Populating Next Right Pointers in Each Node".What if the given tree could be any binary tree? Would your previous solution still work?Note:You may only use constant extra space.For example,Given the following binary tree,
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摘要：Populating Next Right Pointers in Each NodeGiven a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkNode *next; }Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set toNULL.In...
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摘要：Pascal's Triangle IIGiven an indexk, return thekthrow of the Pascal's triangle.For example, givenk= 3,Return[1,3,3,1].Note:Could you optimize your algorithm to use onlyO(k) extra space?和118基本没区别吧…… 1 class Solution { 2 public: 3 vector getRow(int rowIndex) { 4 // Start typing your C/C++ ...
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摘要：Pascal's TriangleGivennumRows, 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]]没啥好说的。。。 1 class Solution { 2 public: 3 vector > generate(int numRows) { 4 // Start typing your C/C++ solution below 5 ...
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摘要：Word LadderGiven two words (startandend), and a dictionary, find the length of shortest transformation sequence fromstarttoend, such that:Only one letter can be changed at a timeEach intermediate word must exist in the dictionaryFor example,Given:start="hit"end="cog"dict=["h
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摘要：Valid PalindromeGiven 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"isnota palindrome.Note:Have you consider that the string might be empty? This is a
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摘要：Binary Tree Maximum Path SumGiven a binary tree, find the maximum path sum.The path may start and end at any node in the tree.For example:Given the below binary tree, 1 / \ 2 3Return6.二叉树后序历遍的变形。 1 /** 2 * Definition for binary tree 3 * struct TreeNode { 4 * int val; 5 * ...
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摘要：Reverse IntegerReverse digits of an integer.Example1:x = 123, return 321Example2:x = -123, return -321做大水题有益于身心健康…… 1 class Solution { 2 public: 3 int reverse(int x) { 4 // Start typing your C/C++ solution below 5 // DO NOT write int main() function 6 int sign = 1, tens =...
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摘要：Sqrt(x)Implementint sqrt(int x).Compute and return the square root ofx.二分，鉴于返回值要int，精度搞到0.1即可…… 1 class Solution { 2 public: 3 4 inline double dabs(double d) { 5 return d > 0 ? d : -d; 6 } 7 8 int sqrt(int x) { 9 // Start typing your C/C++ solution below10 /...
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摘要：Best Time to Buy and Sell Stock IIISay you have an array for which theithelement is the price of a given stock on dayi.Design an algorithm to find the maximum profit. You may complete at mosttwotransactions.Note:You may not engage in multiple transactions at the same time (ie, you must sell the stoc
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摘要：Best Time to Buy and Sell Stock IISay you have an array for which theithelement is the price of a given stock on dayi.Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one share of the stock multiple times). However, you may not e
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摘要：Best Time to Buy and Sell StockSay you have an array for which theithelement is the price of a given stock on dayi.If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an algorithm to find the maximum profit.很水，没什么好说的。 1 class Solution
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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->1->4->3.Your algorithm should use only constant space. You maynotmodify the values in the list, only nodes itself can be changed.嗯，
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摘要：Distinct SubsequencesGiven a stringSand a stringT, count the number of distinct subsequences ofTinS.A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining character
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摘要：Merge k Sorted ListsMergeksorted linked lists and return it as one sorted list. Analyze and describe its complexity.嗯……没啥好说的…… 1 /** 2 * Definition for singly-linked list. 3 * struct ListNode { 4 * int val; 5 * ListNode *next; 6 * ListNode(int x) : val(x), next(NULL) {} 7 * }; 8 *...
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摘要：TriangleGiven a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.For example, given the following triangle[ [2], [3,4], [6,5,7], [4,1,8,3]]The minimum path sum from top to bottom is11(i.e.,2+3+5+1= 11).Note:Bonus point if y...
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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 have the following 3 operations permitted on a word:a) Insert a characterb) Delete a characterc) Replace a characterDP特训第一弹~某种情况下的最小路径，就是分别增、删、改所产生结果
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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 contain a single digit. Add the two numbers and return it as a linked list.Input:(2 -> 4 -> 3) + (5 -> 6 -> 4)Output:7 -> 0 -> 8破题，就是困
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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, please do not see below and ask yourself what are the possible input cases.Notes:It is intended for this problem to be specified vaguely (ie, no given inp
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