CodesKiller - 博客园

2017年2月28日

105. Construct Binary Tree from Preorder and Inorder Traversal

摘要： Given preorder and inorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. 本题通过前序和中序来推断这阅读全文

posted @ 2017-02-28 06:52 CodesKiller 阅读(145) 评论(0) 推荐(0) 编辑

递归，分治算法，动态规划和贪心选择的区别

摘要：一般实际生活中我们遇到的算法分为四类：一>判定性问题二>最优化问题三>构造性问题四>计算性问题而今天所要总结的算法就是着重解决最优化问题《算法之道》对三种算法进行了归纳总结，如下表所示：标准分治动态规划贪心算法适用类型通用问题优化问题优化问题子问题结构每个子问题不同阅读全文

posted @ 2017-02-28 06:46 CodesKiller 阅读(16597) 评论(2) 推荐(4) 编辑

2017年2月15日

442. Find All Duplicates in an Array

摘要： Given an array of integers, 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once. Find all the elements that appear twi 阅读全文

posted @ 2017-02-15 14:51 CodesKiller 阅读(140) 评论(0) 推荐(0) 编辑

448. Find All Numbers Disappeared in an Array

摘要： Given an array of integers where 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once. Find all the elements of [1, n] 阅读全文

posted @ 2017-02-15 14:34 CodesKiller 阅读(124) 评论(0) 推荐(0) 编辑

55. Jump Game

摘要： Given an array of non-negative integers, you are initially positioned at the first index of the array. Each element in the array represents your maxim 阅读全文

posted @ 2017-02-15 14:09 CodesKiller 阅读(123) 评论(0) 推荐(0) 编辑

367. Valid Perfect Square

摘要： Given a positive integer num, write a function which returns True if num is a perfect square else False. Note: Do not use any built-in library functio 阅读全文

posted @ 2017-02-15 13:38 CodesKiller 阅读(161) 评论(0) 推荐(0) 编辑

22. Generate Parentheses

摘要： Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. For example, given n = 3, a solution set is: 阅读全文

posted @ 2017-02-15 13:25 CodesKiller 阅读(114) 评论(0) 推荐(0) 编辑

2017年2月13日

254. Factor Combinations

摘要： Numbers can be regarded as product of its factors. For example, Write a function that takes an integer n and return all possible combinations of its f 阅读全文

posted @ 2017-02-13 14:13 CodesKiller 阅读(110) 评论(0) 推荐(0) 编辑

2017年2月12日

77. Combinations

摘要： Given two integers n and k, return all possible combinations of k numbers out of 1 ... n. For example,If n = 4 and k = 2, a solution is: [ [2,4], [3,4 阅读全文

posted @ 2017-02-12 07:08 CodesKiller 阅读(130) 评论(0) 推荐(0) 编辑

2017年2月11日

17. Letter Combinations of a Phone Number

摘要： Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telepho 阅读全文

posted @ 2017-02-11 14:59 CodesKiller 阅读(151) 评论(0) 推荐(0) 编辑

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