Andrew9tech-优快云博客

原创 python 全排列

itertools模块现成的全排列：for i in itertools.permutations('abcd',4): print ''.join(i)相关全排列算法：def perm(l): if(len(l)<=1): return [l] r=[] for i in range(len(l)):

2015-08-09 11:12:55 825

原创决策树--Python实现

信息增益导入模块：from math import logimport operator计算给定数据集的香农熵：def calcShannonEnt(dataSet): numEntries = len(dataSet) lableCounts = {} for featVec in dataSet: currentLable =

2015-08-03 09:52:13 763

原创 Leetcode Best Time to Buy and Sell Stock II

class Solution: # @param {integer[]} prices # @return {integer} def maxProfit(self, prices): profit = 0; for i in xrange(1, len(prices)): if prices[i] > prices[

2015-07-04 17:11:41 744

原创 Leetcode 121 Best Time to Buy and Sell Stock

class Solution: # @param {integer[]} prices # @return {integer} def maxProfit(self, prices): if len(prices) <= 1: return 0 low = prices[0]; mostProfit = 0 for i

2015-07-04 17:10:30 902

原创 Leetcode 221 Maximal Square

class Solution: # @param {character[][]} matrix # @return {integer} def maximalSquare(self, matrix): if matrix == []: return 0 m, n = len(matrix), len(matrix[0])

2015-07-04 17:09:34 872

原创 Leetcode 96 Unique Binary Search Trees

class Solution: # @param {integer} n # @return {integer} def numTrees(self, n): dp = [0]*(n+1); dp[0] = 1 for nodeNum in range(1,n+1): for k in range(nodeNum):

2015-07-04 17:08:39 393

原创 Leetcode 70 Climbing Stairs

class Solution: # @param {integer} n # @return {integer} def climbStairs(self, n): dp = [0, 1, 2] i = 3 while i <= n: dp.append(dp[i-1] + dp[i-2])

2015-07-04 17:07:38 364

原创 Leetcode 198 House Robber

class Solution: # @param {integer[]} nums # @return {integer} def rob(self, nums): total0,total1 = 0,0 for item in nums: total0,total1 = max(total0,total1), tot

2015-07-04 17:05:34 489

原创 Leetcode 166 Fraction to Recurring Decimal

class Solution: # @param {integer} numerator # @param {integer} denominator # @return {string} def fractionToDecimal(self, numerator, denominator): negativeFlag = numerator * d

2015-07-04 14:33:15 834

原创 Leetcode 187 Repeated DNA Sequences

class Solution: # @param {string} s # @return {string[]} def findRepeatedDnaSequences(self, s): ans = [] valCnt = dict() map = {'A' : 0, 'C' : 1, 'G': 2, 'T' : 3}

2015-07-04 14:31:53 826

原创 Leetcode 94 Binary Tree Inorder Traversal

# Definition for a binary tree node.# class TreeNode:# def __init__(self, x):# self.val = x# self.left = None# self.right = Noneclass Solution: # @param {TreeNod

2015-07-04 14:29:40 362

原创 Leetcode 136 Single Number

class Solution: # @param {integer[]} nums # @return {integer} def singleNumber(self, nums): dictNum = {} for i in xrange(len(nums)): dictNum[nums[i]] = dictNum.

2015-07-04 14:28:30 426

原创 Leetcode 49 Anagrams

class Solution: # @param {string[]} strs # @return {string[]} def anagrams(self, strs): dict = {} for word in strs: sortedword = ''.join(sorted(word))

2015-07-04 14:27:17 430

原创 Leetcode 204 Count Primes

class Solution: # @param {integer} n # @return {integer} def countPrimes(self, n): isPrime = [True] * max(n, 2) isPrime[0]=False; isPrime[1]=False x = 2 whi

2015-07-04 14:26:04 372

原创 Leetcode 202 Happy Number

class Solution: # @param {integer} n # @return {boolean} def isHappy(self, n): squart = dict([(i, int(i)**2) for i in '0123456789']) numSet = set() while n != 1 and

2015-07-04 14:24:01 431

原创 Leetcode 217 Contains Duplicate

class Solution: # @param {integer[]} nums # @return {boolean} def containsDuplicate(self, nums): dictNum = {} for i in range(len(nums)): dictNum[nums[i]] = dict

2015-07-04 14:23:10 366

原创 Leetcode 219 Contains Duplicate II

class Solution: # @param {integer[]} nums # @param {integer} k # @return {boolean} def containsNearbyDuplicate(self, nums, k): dictNums = {} for i in range(len(nums)):

2015-07-04 14:22:05 421

原创 Leetcode 43 Multiply Strings

class Solution: # @param {string} num1 # @param {string} num2 # @return {string} def multiply(self, num1, num2): if num1 == "0" or num2 == "0": return "0"

2015-07-01 15:46:52 698

原创 Leetcode 41 First Missing Positive

class Solution: # @param {integer[]} nums # @return {integer} def firstMissingPositive(self, nums): Length = len(nums) for i in range(Length): while nums[i] !=

2015-06-23 17:18:42 598

原创 Leetcode 38 Sudoku Solver

Sudoku Solverclass Solution: # @param {character[][]} board # @return {void} Do not return anything, modify board in-place instead. def solveSudoku(self, board): def c

2015-06-23 10:02:12 596

原创 python decode()、encode() 、编码与反编码

python中提到unicode，一般指的是unicode对象，比如：“叫我”的对象为'\u53eb\u6211''.字符串在Python内部的表示是unicode编码，因此，在做编码转换时，通常需要以unicode作为中间编码，即先将其他编码的字符串解码（decode）成unicode，再从unicode编码（encode）成另一种编码。decode的作用是将其他编码的字符串转换成uni

2015-05-24 18:03:57 919

原创 Leetcode 38 Count and Say

class Solution: # @param {integer} n # @return {string} def countAndSay(self, n): str = "1" for i in range(n-1): temp = str; str = ""; count = 1 for

2015-05-22 00:22:42 287

原创 Leetcode 36 Valid Sudoku

三次9*9 循环，效率不高吧class Solution: # @param {character[][]} board # @return {boolean} def isValidSudoku(self, board): if len(board)!=9 or len(board[0])!=9: return False

2015-05-21 18:40:30 563

原创 Leetcode 35 Search Insert Position

class Solution: # @param {integer[]} nums # @param {integer} target # @return {integer} def searchInsert(self, nums, target): left, right = 0, len(nums)-1 while left <=

2015-05-21 13:07:55 550

原创 Leetcode 34 Search for a Range

class Solution: # @param {integer[]} nums # @param {integer} target # @return {integer[]} def searchRange(self, nums, target): if target in nums: result = []

2015-05-21 11:55:59 491

原创 Leetcode 33 Search in Rotated Sorted Array

class Solution: # @param {integer[]} nums # @param {integer} target # @return {integer} def search(self, nums, target): for i in xrange(len(nums)): if nums[i]==targ

2015-05-21 10:19:20 367

原创 Leetcode 32 Longest Valid Parentheses

class Solution: # @param {string} s # @return {integer} def longestValidParentheses(self, s): if len(s)<2: return 0 result = 0; stack = [(-1, ')')] for

2015-05-21 09:29:11 299

原创 Leetcode 30 Substring with Concatenation of All Words

class Solution: # @param {string} s # @param {string[]} words # @return {integer[]} def findSubstring(self, s, words): lenS=len(s);lenL=len(words);lenW=len(words[0]) re

2015-05-20 13:47:37 440

原创 Leetcode 24 Swap Nodes in Pairs

# Definition for singly-linked list.# class ListNode:# def __init__(self, x):# self.val = x# self.next = Noneclass Solution: # @param {ListNode} head # @return {ListN

2015-05-20 12:48:10 373

原创 Leetcode 29 Divide Two Integers

class Solution: # @param {integer} dividend # @param {integer} divisor # @return {integer} def divide(self, dividend, divisor): if(dividend 0) or (dividend > 0 and divisor < 0

2015-05-19 02:23:39 327

原创 Leetcode 28 Implement strStr()

暴力匹配，时间复杂度为O(n*n)，建议KMPclass Solution: # @param {string} haystack # @param {string} needle # @return {integer} def strStr(self, haystack, needle): if len(haystack) < len(need

2015-05-19 01:45:50 312

原创 Leetcode 27 Remove Element

class Solution: # @param {integer[]} nums # @param {integer} val # @return {integer} def removeElement(self, nums, val): Length = len(nums);size = 0 if Length==0: retur

2015-05-19 01:15:18 312

原创 Leetcode 26 Remove Duplicates from Sorted Array

class Solution: # @param {integer[]} nums # @return {integer} def removeDuplicates(self, nums): Length = len(nums);size = 0 if Length==0: return 0 for i in range(Le

2015-05-19 01:02:08 324

原创 Leetcode 25 Reverse Nodes in k-Group

class Solution: # @param {ListNode} head # @param {integer} k # @return {ListNode} def reverse(self,start,end): head = ListNode(0);head.next=start while head.next!=end:

2015-05-19 01:01:28 520

原创 Leetcode 17 Letter Combinations of a Phone Number

class Solution: # @param {string} digits # @return {string[]} def letterCombinations(self, digits): alpha = [" ", "1", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"]

2015-05-18 23:01:29 392

原创 Leetcode 23 Merge k Sorted Lists

# Definition for singly-linked list.# class ListNode:# def __init__(self, x):# self.val = x# self.next = Noneclass Solution: # @param {ListNode[]} lists # @return {Li

2015-05-18 16:51:52 451

原创 Python heapq模块

heapq模块提供了如下几个函数：heapq.heappush(heap, item) 把item添加到heap中（heap是一个列表）heapq.heappop(heap) 把堆顶元素弹出，返回的就是堆顶heapq.heappushpop(heap, item) 先把item加入到堆中，然后再pop，比heappush()再heappop()要快得多h

2015-05-18 16:30:22 418

原创 Leetcode 22 Generate Parentheses

递归：class Solution: # @param {integer} n # @return {string[]} def generateParenthesis(self, n): def Recursive(left,right,string,res): if left==0 and right==0:

2015-05-18 15:27:45 304

原创 Leetcode 21 Merge Two Sorted Lists

class Solution: # @param {ListNode} l1 # @param {ListNode} l2 # @return {ListNode} def mergeTwoLists(self, l1, l2): head=ListNode(0) temp = head if l1 == None:

2015-05-18 12:55:08 255

原创 Leetcode 20 Valid Parentheses

class Solution: # @param {string} s # @return {boolean} def isValid(self, s): Length = len(s) List = [] for i in range(Length): if s[i] == '(' or s[i] =

2015-05-18 12:07:33 276

空空如也

空空如也