随笔分类 -  LeetCode

你说离开是为了更好的相见,我说再好的重逢也终究会离开



摘要:233 Number of Digit One这道题是递归算法class Solution: # @param {integer} n # @return {integer} def countDigitOne(self, n): if n <= 0: ... 阅读全文
posted @ 2015-08-12 05:27 dapanshe 阅读(110) 评论(0) 推荐(0)
摘要:018 4Sum感觉最差的情况应该是O(n*n*n)的复杂度from collections import defaultdictclass Solution: # @param {integer[]} nums # @param {integer} target # @retur... 阅读全文
posted @ 2015-08-10 12:51 dapanshe 阅读(117) 评论(0) 推荐(0)
摘要:029 Divide Two Integersclass Solution: # @param {integer} dividend # @param {integer} divisor # @return {integer} def divide(self, dividen... 阅读全文
posted @ 2015-08-08 14:39 dapanshe 阅读(111) 评论(0) 推荐(0)
摘要:166 Fraction to Recurring Decimal这道题就是不停的去check做除法的余数是否重复出现了class Solution: # @param {integer} numerator # @param {integer} denominator # @re... 阅读全文
posted @ 2015-08-07 14:00 dapanshe 阅读(128) 评论(0) 推荐(0)
摘要:220 Contains Duplicate III这道题用dic来记录上一次桶区间内的下标,唯一的trick是比较周边的一共三个桶class Solution: # @param {integer[]} nums # @param {integer} k # @param {in... 阅读全文
posted @ 2015-08-07 02:46 dapanshe 阅读(135) 评论(0) 推荐(0)
摘要:099 Recover Binary Search Tree没有按照要求用 constant space.... 用valid BST 找出两个not in order 的nodesclass Solution: def recoverTree(self, root): [fN,... 阅读全文
posted @ 2015-08-06 05:25 dapanshe 阅读(111) 评论(0) 推荐(0)
摘要:105 Construct Binary Tree from Preorder and Inorder Traversal这道题纯递归class Solution: # @param {integer[]} preorder # @param {integer[]} inorder ... 阅读全文
posted @ 2015-08-06 01:45 dapanshe 阅读(114) 评论(0) 推荐(0)
摘要:214 Shortest Palindrome这道题会用到一个算法在 这里用过利用这个算法稍作改进即可class Solution: def shortestPalindrome(self, s): T = '#'.join('${}&'.format(s)) an... 阅读全文
posted @ 2015-08-06 00:34 dapanshe 阅读(104) 评论(0) 推荐(0)
摘要:132 Palindrome Partitioning II这道题就是标识出s[i:j+1]是否为palindrome, 然后dp找出最小分割class Solution: # @param {string} s # @return {integer} def minCut(sel... 阅读全文
posted @ 2015-08-05 00:56 dapanshe 阅读(111) 评论(0) 推荐(0)
摘要:131 Palindrome Partitioning这道题先是标识出所有的 s[i:j+1] 是否为 palindrome, 然后在暴力搜索就好class Solution: def __init__(self): self.dp = [] self.ans = ... 阅读全文
posted @ 2015-08-05 00:55 dapanshe 阅读(111) 评论(0) 推荐(0)
摘要:005 Longest Palindromic Substring这道题比较常见的是 O(n*n)的解法 网上有一个十分巧妙的算法Manacher’s Algorithm根据这个算法的代码如下class Solution: # @return a string def longestPa... 阅读全文
posted @ 2015-08-03 12:43 dapanshe 阅读(119) 评论(0) 推荐(0)
摘要:087 Scramble String这道题是divide and conquer。 使用sorted可以快速判断 要不然会超时class Solution: # @param {string} s1 # @param {string} s2 # @return {boolean}... 阅读全文
posted @ 2015-08-01 11:48 dapanshe 阅读(98) 评论(0) 推荐(0)
摘要:037 Sudoku Solver这道题我纯暴力搜了 肯定可以优化, 懒得去看了。。。class Solution: def __init__(self): self.b = [] def solveSudoku(self, board): self.... 阅读全文
posted @ 2015-08-01 01:50 dapanshe 阅读(119) 评论(0) 推荐(0)
摘要:097 Interleaving String这道题也是纯dp了class Solution: # @param {string} s1 # @param {string} s2 # @param {string} s3 # @return {boolean} def ... 阅读全文
posted @ 2015-07-30 00:23 dapanshe 阅读(119) 评论(0) 推荐(0)
摘要:91 Decode Waysdp解法 O(1) spaceclass Solution: # @param {string} s # @return {integer} def numDecodings(self, s): if s == "" or s[0] == ... 阅读全文
posted @ 2015-07-29 15:33 dapanshe 阅读(125) 评论(0) 推荐(0)
摘要:022 Generate Parentheses纯递归解法class Solution: def __init__(self): self.ans = [] def generateParenthesis(self, n): self.help(n, ... 阅读全文
posted @ 2015-07-29 14:25 dapanshe 阅读(128) 评论(0) 推荐(0)
摘要:240 Search a 2D Matrix II这是个young‘s矩阵,最好的就是O(m+n)的算法了class Solution: # @param {integer[][]} matrix # @param {integer} target # @return {boole... 阅读全文
posted @ 2015-07-24 04:50 dapanshe 阅读(129) 评论(0) 推荐(0)
摘要:103 Binary Tree Zigzag Level Order Traversallevel traversal的变种class Solution: # @param {TreeNode} root # @return {integer[][]} def zigzagLeve... 阅读全文
posted @ 2015-07-23 02:38 dapanshe 阅读(132) 评论(0) 推荐(0)
摘要:108 Convert Sorted Array to Binary Search Tree递归解法还是非常直观的class Solution: # @param {integer[]} nums # @return {TreeNode} def sortedArrayToBST(... 阅读全文
posted @ 2015-07-23 02:29 dapanshe 阅读(98) 评论(0) 推荐(0)
摘要:117 Populating Next Right Pointers in Each Node II就是 Bibary Tree Level order Traverseclass Solution: # @param root, a tree link node # @return n... 阅读全文
posted @ 2015-07-23 01:45 dapanshe 阅读(141) 评论(0) 推荐(0)