copperface - 博客园

2017年2月6日

摘要： 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 filled sudoku which... 阅读全文

posted @ 2017-02-06 14:42 copperface 阅读(144) 评论(0) 推荐(0)

2017年2月4日

29. Divide Two Integers

摘要： Divide two integers without using multiplication, division and mod operator.If it is overflow, return MAX_INT.分析不能用除法，所以使用减法不断减除数，同时对除数倍乘，进行加速除数：3 -> 6 -> 12 ...边界条件：1 除数为0，溢出2 被除数 INT_MIN，同时除数 -1，... 阅读全文

posted @ 2017-02-04 17:18 copperface 阅读(126) 评论(0) 推荐(0)

32. Longest Valid Parentheses

摘要： Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring.For "(()", the longest valid parentheses substring is "()", which ha... 阅读全文

posted @ 2017-02-04 17:17 copperface 阅读(166) 评论(0) 推荐(0)

34. Search for a Range

摘要： Given an array of integers sorted in ascending order, find the starting and ending position of a given target value.Your algorithm's runtime complexity must be in the order of O(log n).If the target i... 阅读全文

posted @ 2017-02-04 17:16 copperface 阅读(159) 评论(0) 推荐(0)

33. Search in Rotated Sorted Array

摘要： Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).You are given a target value to search. If found in the a... 阅读全文

posted @ 2017-02-04 11:14 copperface 阅读(166) 评论(0) 推荐(0)

2017年1月24日

31. Next Permutation

摘要： Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.If such arrangement is not possible, it must rearrange it as the lowest possible ord... 阅读全文

posted @ 2017-01-24 15:51 copperface 阅读(194) 评论(0) 推荐(0)

30. Substring with Concatenation of All Words

摘要： You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of substring(s) in s that is a concatenation of each word in words exactly once and wi... 阅读全文

posted @ 2017-01-24 12:42 copperface 阅读(250) 评论(0) 推荐(0)

2017年1月18日

Knuth-Morris-Pratt Algorithm

摘要： KMP背景分析普通算法（遍历），会遗忘所有之前比较过的信息，导致每一次移位，都要重新重头比较每一个字符。这将会导致 O(mn)的时间复杂度（m: 关键字符长度，n: 文本string的长度）而KMP算法，则能够保证不去重复比较已经部分匹配的字符，比如序列“abcdabac”，如果“abcd”部分匹配了文本，而在接下来的“a”位置上不匹配，那么算法则会直接跳过4个位置，重新进行比较，而不是移位1个，... 阅读全文

posted @ 2017-01-18 09:43 copperface 阅读(664) 评论(0) 推荐(0)

2017年1月17日

28. Implement strStr()

摘要： Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.分析这就是字符串匹配算法算法一：brute forcetime complexity: O(nm)space complexity: O(1)12345... 阅读全文

posted @ 2017-01-17 22:27 copperface 阅读(161) 评论(0) 推荐(0)

2017年1月13日

24. Swap Nodes in Pairs

摘要： Given a linked list, swap every two adjacent nodes and return its head.For example,Given 1->2->3->4, you should return the list as 2->1->4->3.Your algorithm should use only constant space. You may not... 阅读全文

posted @ 2017-01-13 14:04 copperface 阅读(153) 评论(0) 推荐(0)

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