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 of the two subtrees of every node never differ by more than 1.class Solution {public: bool f(TreeNode *root, int & height){ if (!root){ ... 阅读全文

摘要： Given a set ofnon-overlappingintervals, insert a new interval into the intervals (merge if necessary).You may assume that the intervals were initially sorted according to their start times.Example 1:Given intervals[1,3],[6,9], insert and merge[2,5]in as[1,5],[6,9].Example 2:Given[1,2],[3,5],[6,7],[8 阅读全文

摘要： MIT的算法课，看到一个很新颖的Partition的方法，代码很简洁，在也不用判断几个边界(original i#include using namespace std;//Partition a[begin,end)/** [p| = x | unknow ] i j 6 10 13 5 8 3 2 || x=6 i j j if ok 6 5 13 10 8 3 2 i j =x MIT 算法导论课的Partition算法 Partition(A,p,q) //... 阅读全文

摘要： Given a string containing only digits, restore it by returning all possible valid IP address combinations.For example:Given"25525511135",return["255.255.11.135", "255.255.111.35"]. (Order does not matter)class Solution {public: vector ans; vector restoreIpAddresses(stri 阅读全文

摘要： Given a collection of candidate numbers (C) and a target number (T), find all unique combinations inCwhere the candidate numbers sums toT.Each number inCmay only be usedoncein the combination.Note:All numbers (including target) will be positive integers.Elements in a combination (a1,a2, � ,ak) must 阅读全文

摘要： Given a set of candidate numbers (C) and a target number (T), find all unique combinations inCwhere the candidate numbers sums toT.Thesamerepeated number may be chosen fromCunlimited number of times.Note:All numbers (including target) will be positive integers.Elements in a combination (a1,a2, � ,ak 阅读全文

摘要： Given 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 multiple ofkthen left-out nodes in the end should remain as it is.You may not alter the values in the nodes, only nodes itself may be changed.Only constant memory is allowed 阅读全文

摘要： Implement strStr().Returns a pointer to the first occurrence of needle in haystack, ornullif needle is not part of haystack.思路：朴素算法和KMP，此外还有Karbin-ship算法。关于next的数组，只需要知道一点：求patten串i位置(包括自己)最大前缀子串的长度，这个长度其实就是将来i+1的位置失配之后，下一次j重新比较的位置。也可以理解为一个dp的过程#include <iostream>#include <string.h>#incl 阅读全文

摘要： Implement wildcard pattern matching with support for'?'and'*'.'?' Matches any single character.'*' Matches any sequence of characters (including the empty sequence).The matching should cover the entire input string (not partial).The function prototype should be:bool i 阅读全文

摘要： Two elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Note:A solution using O(n) space is pretty straight forward. Could you devise a constant space solution?思路：BST就是对应的InOrder，1) 那么只需要InOrder，维持一个当前的Val，然后看下一个是不是比当前的大，如果不大，则记录位置，直到找到2个位置fi 阅读全文