cha1992

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 ... 阅读全文

摘要： Pow(x, n)Implement pow(x,n).思路：分治算法，2^4=（2^2）*（2^2）。整体的思路就是这样，要注意考虑n为负数的情况。我的做法是在写一个函数计算乘方，原来的函数根据n的正负选择如何调用power函数。开始的时候，没有用tmp保存power(x,n/2)的值，直接写成p... 阅读全文

摘要： Longest Common PrefixWrite a function to find the longest common prefix string amongst an array of strings.思路：找最长前缀，暴力法寻找。遍历整个容器，prefix记录了当前的最长前缀，将pre... 阅读全文

摘要： Binary Tree Zigzag Level Order TraversalGiven a binary tree, return thezigzag level ordertraversal of its nodes' values. (ie, from left to right, then... 阅读全文

摘要： Construct Binary Tree from Preorder and Inorder TraversalGiven preorder and inorder traversal of a tree, construct the binary tree.Note:You may assume... 阅读全文

摘要： Construct Binary Tree from Inorder and Postorder TraversalGiven inorder and postorder traversal of a tree, construct the binary tree.Note:You may assu... 阅读全文

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... 阅读全文

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... 阅读全文

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... 阅读全文

摘要： Excel Sheet Column TitleGiven a positive integer, return its corresponding column title as appear in an Excel sheet.For example: 1 -> A 2 -> B ... 阅读全文