From c6369b74b28f9efd243da87cd9651c18d76101e5 Mon Sep 17 00:00:00 2001 From: "Jack.ht.lee" Date: Tue, 6 Sep 2016 13:50:06 +0800 Subject: [PATCH 01/10] Create 7. Reverse Integer QuestionEditorial Solution --- ...everse Integer QuestionEditorial Solution | 35 +++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 leetcode/7. Reverse Integer QuestionEditorial Solution diff --git a/leetcode/7. Reverse Integer QuestionEditorial Solution b/leetcode/7. Reverse Integer QuestionEditorial Solution new file mode 100644 index 0000000..acc9d2d --- /dev/null +++ b/leetcode/7. Reverse Integer QuestionEditorial Solution @@ -0,0 +1,35 @@ +''' +Reverse digits of an integer. + +Example1: x = 123, return 321 +Example2: x = -123, return -321 + +''' + +class Solution(object): + def reverse(self, x): + res = int(str(abs(x))[::-1]) + if x < 0: + res = -res + if res > 2147483647 or res < -2147483648: + res = 0 + return res + # without str() + def reverse2(self, x): from math import log + if x < 10 and x > -10: + return x + flipped = False + if x < 0: + flipped = True + x *= -1 + res = 0 + log10 = int(log(x, 10)) + for i in xrange(log10 + 1): + digit = x % 10 + res += digit * 10**(log10 - i) + x /= 10 + if res > 2**31 - 1 or res < -1 * 2**31 + 1: + return 0 + if flipped: + res *= -1 + return res From 3e5e26463db4b74e866ad24f0fe866b91ed79f8c Mon Sep 17 00:00:00 2001 From: "Jack.ht.lee" Date: Fri, 9 Sep 2016 14:07:00 +0800 Subject: [PATCH 02/10] add leetcode 143 --- .idea/workspace.xml | 21 +++++++------ leetcode/143. Reorder List.py | 57 +++++++++++++++++++++++++++++++++++ 2 files changed, 68 insertions(+), 10 deletions(-) create mode 100644 leetcode/143. Reorder List.py diff --git a/.idea/workspace.xml b/.idea/workspace.xml index a84d8f4..7657e1d 100644 --- a/.idea/workspace.xml +++ b/.idea/workspace.xml @@ -2,7 +2,7 @@ - + @@ -83,7 +83,6 @@ @@ -169,6 +169,7 @@ + @@ -203,7 +204,6 @@ - @@ -545,13 +545,6 @@ - - - - - - - @@ -892,6 +885,14 @@ + + + + + + + + diff --git a/leetcode/143. Reorder List.py b/leetcode/143. Reorder List.py new file mode 100644 index 0000000..838b15c --- /dev/null +++ b/leetcode/143. Reorder List.py @@ -0,0 +1,57 @@ +''' +Given a singly linked list L: L0→L1→…→Ln-1→Ln, +reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… + +You must do this in-place without altering the nodes' values. + +For example, +Given {1,2,3,4}, reorder it to {1,4,2,3}. +''' + + +# Definition for singly-linked list. +class ListNode(object): + def __init__(self, x): + self.val = x + self.next = None + +class Solution(object): + def reorderList(self, head): + if not head or not head.next: + return + ahead, behind = self.split(head) + behind = self.reverse(behind) + head = self.reConnect(ahead, behind) + # split the linkedlist in middle + def split(self, head): + fast = head + slow = head + while fast and fast.next: + slow = slow.next + fast = fast.next + fast = fast.next + middle = slow.next + slow.next = None + return head, middle + # reverse the behind half linkedlist + def reverse(self, head): + reHead = None + curNode = head + while curNode: + nextNode = curNode.next + curNode.next = reHead + reHead = curNode + curNode = nextNode + return reHead + # merge the two linkedlist to one + def reConnect(self, first, second): + head = first + tail = first + first = first.next + while second: + tail.next = second + tail = tail.next + second = second.next + if first: + first, second = second, first + return head \ No newline at end of file From eb51c41690273bcb479fa03781a001ad86d205ec Mon Sep 17 00:00:00 2001 From: "Jack.ht.lee" Date: Sun, 11 Sep 2016 16:09:37 +0800 Subject: [PATCH 03/10] =?UTF-8?q?=E9=9B=B6=E9=92=B1=E6=89=BE=E9=9B=B6=20?= =?UTF-8?q?=E7=BE=8E=E5=9B=A2=E7=AC=94=E8=AF=95=E9=A2=98?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...3\245\345\217\212\350\277\233\351\230\266" | 40 +++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 "Target Offer/\351\233\266\351\222\261\346\211\276\351\233\266\344\273\245\345\217\212\350\277\233\351\230\266" diff --git "a/Target Offer/\351\233\266\351\222\261\346\211\276\351\233\266\344\273\245\345\217\212\350\277\233\351\230\266" "b/Target Offer/\351\233\266\351\222\261\346\211\276\351\233\266\344\273\245\345\217\212\350\277\233\351\230\266" new file mode 100644 index 0000000..0094fd3 --- /dev/null +++ "b/Target Offer/\351\233\266\351\222\261\346\211\276\351\233\266\344\273\245\345\217\212\350\277\233\351\230\266" @@ -0,0 +1,40 @@ +''' +零钱找零问题，使用动态规划 +''' +def ChangeMaking(coinVal, change): + alist = [0]*(change+1) + for i in range(1, change+1): + temp = change; j = 0 + while j <= len(coinVal)-1 and i >= coinVal[j]: + temp = min(alist[i-coinVal[j]], temp) + j += 1 + alist[i] = temp + 1 + return alist.pop() + +print(ChangeMaking([1, 5, 10, 25], 63)) + +''' +零钱找零问题的进阶 +美团笔试题 +给你六中零钱1,5,10,20,50,100的纸币，给定一个金额，写出所有可能的找零的个数 +输入2，输出1；输入5，输出2 +也是使用动态规划 +''' +import sys +try: + while True: + line = sys.stdin.readline().strip() + if line == '': + break + target = int(line) + coinVal = [1, 5, 10, 20, 50, 100] + alist = [0]*(target+1) + alist[0] = 1 + for i in range(6): + j = coinVal[i] + while j <= target: + alist[j] = alist[j] + alist[j-coinVal[i]] + j += 1 + print(alist[-1]) +except: + pass From 5cc666d7e3313394b50fa5e37aaa3f595edb0c67 Mon Sep 17 00:00:00 2001 From: "Jack.ht.lee" Date: Tue, 13 Sep 2016 23:17:23 +0800 Subject: [PATCH 04/10] Create 4. Median of Two Sorted Arrays --- leetcode/4. Median of Two Sorted Arrays | 49 +++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 leetcode/4. Median of Two Sorted Arrays diff --git a/leetcode/4. Median of Two Sorted Arrays b/leetcode/4. Median of Two Sorted Arrays new file mode 100644 index 0000000..0c74b39 --- /dev/null +++ b/leetcode/4. Median of Two Sorted Arrays @@ -0,0 +1,49 @@ +''' +There are two sorted arrays nums1 and nums2 of size m and n respectively. + +Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)). + +Example 1: +nums1 = [1, 3] +nums2 = [2] + +The median is 2.0 +Example 2: +nums1 = [1, 2] +nums2 = [3, 4] + +The median is (2 + 3)/2 = 2.5 +''' +class Solution(object): + def findMedianSortedArrays(self, a, b): + n = len(a)+len(b) + if n&1: + return self.kthSmallest(a,b,n//2+1) + else: + return (self.kthSmallest(a,b,n//2+1) + self.kthSmallest(a,b,n//2))/2.0 + + def kthSmallest(self,a,b,k): + if len(a)+len(b) < k: + return None + i=0 + j=0 + flag = True + while k>0: + if i >= len(a): + j+=1 + flag = False + elif j >= len(b): + i+=1 + flag = True + elif a[i] <= b[j]: + i+=1 + flag = True + elif a[i] > b[j]: + j+=1 + flag = False + k-=1 + + if flag: + return a[i-1] + else: + return b[j-1] From a916c05f2cc998ffa318734f4f5d97f5af55c4d4 Mon Sep 17 00:00:00 2001 From: "Jack.ht.lee" Date: Tue, 13 Sep 2016 23:23:02 +0800 Subject: [PATCH 05/10] Create 322. Coin Change --- leetcode/322. Coin Change | 41 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 leetcode/322. Coin Change diff --git a/leetcode/322. Coin Change b/leetcode/322. Coin Change new file mode 100644 index 0000000..f0eb84e --- /dev/null +++ b/leetcode/322. Coin Change @@ -0,0 +1,41 @@ +''' +You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to make up that amount. If that amount of money cannot be made up by any combination of the coins, return -1. + +Example 1: +coins = [1, 2, 5], amount = 11 +return 3 (11 = 5 + 5 + 1) + +Example 2: +coins = [2], amount = 3 +return -1. + +Note: +You may assume that you have an infinite number of each kind of coin. +''' +class Solution(object): + def coinChange(self, coins, amount): + #corner cases + if amount == 0: + return 0 + if len(coins) == 1 and coins[0] > amount: + return -1 + dp = [-1 for i in range(amount + 1)] + for i in range(1, amount + 1): + # if the value matches the coin + if i in coins: + dp[i] = 1 + else: + minV = sys.maxsize + # since the size of coins are much less than the amount, + # we check if for every coin there could be a solution and find the minimum of that + for j in coins: + remain = i - j + # -1 means there is no solution, so we don't need to check if dp[i] is -1 + if remain > 0 and dp[remain] != -1: + minV = min(minV, dp[remain]) + if minV ==sys.maxsize: + dp[i] = -1 + else: + dp[i] = minV + 1 + return dp[-1] + From f1b9f603defd11b1e2db29fdd0a6f26c16cc2608 Mon Sep 17 00:00:00 2001 From: "Jack.ht.lee" Date: Tue, 13 Sep 2016 23:29:24 +0800 Subject: [PATCH 06/10] Create 337. House Robber III --- leetcode/337. House Robber III | 44 ++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 leetcode/337. House Robber III diff --git a/leetcode/337. House Robber III b/leetcode/337. House Robber III new file mode 100644 index 0000000..c5cd083 --- /dev/null +++ b/leetcode/337. House Robber III @@ -0,0 +1,44 @@ +''' +The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the "root." Besides the root, each house has one and only one parent house. After a tour, the smart thief realized that "all houses in this place forms a binary tree". It will automatically contact the police if two directly-linked houses were broken into on the same night. + +Determine the maximum amount of money the thief can rob tonight without alerting the police. + +Example 1: + 3 + / \ + 2 3 + \ \ + 3 1 +Maximum amount of money the thief can rob = 3 + 3 + 1 = 7. +Example 2: + 3 + / \ + 4 5 + / \ \ + 1 3 1 +Maximum amount of money the thief can rob = 4 + 5 = 9. +''' +# Definition for a binary tree node. +# class TreeNode(object): +# def __init__(self, x): +# self.val = x +# self.left = None +# self.right = None + +class Solution(object): + def rob(self, root): + def gain(root): + if root == None: + return 0 + o1 = root.val + if o1 < 0: + return -o1 + if root.left: + o1 += gain(root.left.left) + gain(root.left.right) + if root.right: + o1 += gain(root.right.left) + gain(root.right.right) + o2 = gain(root.left) + gain(root.right) + o = max(o1,o2) + root.val = -1*o + return o + return gain(root) From ae600869f4f883418864ee92101ecd10a6b86e52 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E7=8E=8B=E6=A3=AE?= <627989472@qq.com> Date: Thu, 4 May 2017 16:32:33 +0800 Subject: [PATCH 07/10] =?UTF-8?q?Update=20=E4=B8=8D=E7=94=A8=E5=8A=A0?= =?UTF-8?q?=E5=87=8F=E4=B9=98=E9=99=A4=E5=81=9A=E5=8A=A0=E6=B3=95.py?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 通过每次对num1进行与操作保证是一个32位的整形，因此最后我们可以判断符号位是否为1做处理。可以使Python AC --- ...44\345\201\232\345\212\240\346\263\225.py" | 27 +++++++++++++------ 1 file changed, 19 insertions(+), 8 deletions(-) diff --git "a/Target Offer/\344\270\215\347\224\250\345\212\240\345\207\217\344\271\230\351\231\244\345\201\232\345\212\240\346\263\225.py" "b/Target Offer/\344\270\215\347\224\250\345\212\240\345\207\217\344\271\230\351\231\244\345\201\232\345\212\240\346\263\225.py" index eef1246..0d8d072 100644 --- "a/Target Offer/\344\270\215\347\224\250\345\212\240\345\207\217\344\271\230\351\231\244\345\201\232\345\212\240\346\263\225.py" +++ "b/Target Offer/\344\270\215\347\224\250\345\212\240\345\207\217\344\271\230\351\231\244\345\201\232\345\212\240\346\263\225.py" @@ -6,13 +6,24 @@ # 可能是python的的整型可以无限大的原因, 导致正数和负数的异或操作不断变成更小的负数而不会溢出 # 使用Swift尝试了一下, 还是可以求得正数和负数的位操作相加运算的 # -*- coding:utf-8 -*- +# class Solution: +# def Add(self, num1, num2): +# while num2: +# sum = num1 ^ num2 +# carry = (num1 & num2) << 1 +# num1 = sum +# num2 = carry +# return num1 +# s = Solution() +# print(s.Add(4, 2)) +# -*- coding:utf-8 -*- +# 通过每次对num1进行与操作保证是一个32位的整形 +# 因此最后我们可以判断符号位是否为1做处理 class Solution: def Add(self, num1, num2): - while num2: - sum = num1 ^ num2 - carry = (num1 & num2) << 1 - num1 = sum - num2 = carry - return num1 -s = Solution() -print(s.Add(4, 2)) + # write code here + while num2 != 0: + temp = num1 ^ num2 + num2 = (num1 & num2) << 1 + num1 = temp & 0xFFFFFFFF + return num1 if num1 >> 31 == 0 else num1 - 4294967296 From 9f0a15e6e7a8fd56813d8f2b2e9a0d59eca61ab9 Mon Sep 17 00:00:00 2001 From: wangershi <33387561+wangershi@users.noreply.github.com> Date: Sun, 5 Nov 2017 15:42:50 +0800 Subject: [PATCH 08/10] =?UTF-8?q?Update=20=E4=BA=8C=E7=BB=B4=E6=95=B0?= =?UTF-8?q?=E7=BB=84=E6=9F=A5=E6=89=BE.py?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 需要判断float是否有小数点，如果有小数点的话float肯定不是整数 --- ...\273\264\346\225\260\347\273\204\346\237\245\346\211\276.py" | 2 ++ 1 file changed, 2 insertions(+) diff --git "a/Target Offer/\344\272\214\347\273\264\346\225\260\347\273\204\346\237\245\346\211\276.py" "b/Target Offer/\344\272\214\347\273\264\346\225\260\347\273\204\346\237\245\346\211\276.py" index 3d05286..81239fd 100644 --- "a/Target Offer/\344\272\214\347\273\264\346\225\260\347\273\204\346\237\245\346\211\276.py" +++ "b/Target Offer/\344\272\214\347\273\264\346\225\260\347\273\204\346\237\245\346\211\276.py" @@ -29,6 +29,8 @@ def Find(self, array, target): # 判断非法输入 # 可以换成 isinstance(target, (int, float)) 进行判断 if type(target) == float and type(array[0][0]) == int: + if int(target) == target: + return False target = int(target) elif type(target) == int and type(array[0][0]) == float: target = float(int) From 85dea78ce6e6988e83d753daf051384a1ab027e6 Mon Sep 17 00:00:00 2001 From: wangershi <33387561+wangershi@users.noreply.github.com> Date: Mon, 6 Nov 2017 19:39:27 +0800 Subject: [PATCH 09/10] =?UTF-8?q?Update=20=E6=9B=BF=E6=8D=A2=E7=A9=BA?= =?UTF-8?q?=E6=A0=BC.py?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit replace1方法和replace2方法都是O(n*m)的时间复杂度，这里m是空格的数量，因为list的insert是一个O(n)的复杂度。 而list的append是一个O(1)的时间复杂度，除了扩容时的时间损耗，append方法只需要遍历一次数组即可得结果。 --- ...233\277\346\215\242\347\251\272\346\240\274.py" | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git "a/Target Offer/\346\233\277\346\215\242\347\251\272\346\240\274.py" "b/Target Offer/\346\233\277\346\215\242\347\251\272\346\240\274.py" index 72e50f2..bd15a41 100644 --- "a/Target Offer/\346\233\277\346\215\242\347\251\272\346\240\274.py" +++ "b/Target Offer/\346\233\277\346\215\242\347\251\272\346\240\274.py" @@ -6,6 +6,20 @@ # -*- coding:utf-8 -*- class Solution: # s 源字符串 + + # 使用append一次遍历即可替换 + # 由于list的append是O(1)的时间复杂度，除了扩容所导致的时间损耗，该算法复杂度为O(n) + def replaceSpaceByAppend(self, s): + string = list(string) + stringReplace = [] + for item in string: + if item == ' ': + stringReplace.append('%') + stringReplace.append('2') + stringReplace.append('0') + else: + stringReplace.append(item) + return "".join(stringReplace) # 创建新的字符串进行替换 def replaceSpace1(self, s): From c4b94d1182d3bd4aa2ddce81dfb5045fbf1de14a Mon Sep 17 00:00:00 2001 From: reece Date: Fri, 17 Aug 2018 17:50:00 +0800 Subject: [PATCH 10/10] fix index out of range --- QuickSort.py | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/QuickSort.py b/QuickSort.py index cd8a673..59b0972 100644 --- a/QuickSort.py +++ b/QuickSort.py @@ -1,3 +1,5 @@ +# coding: utf-8 + def quickSort(alist): quickSortHelper(alist, 0, len(alist)-1) @@ -16,9 +18,9 @@ def partition(alist, first, last): done = False while not done: - while alist[leftmark] <= pivotvlue and leftmark <= rightmark: + while leftmark <= rightmark and alist[leftmark] <= pivotvlue: # bugfix: 先比较index, 不然数组会越界 leftmark += 1 - while alist[rightmark] >= pivotvlue and rightmark >= leftmark: + while rightmark >= leftmark and alist[rightmark] >= pivotvlue: rightmark -= 1 if leftmark > rightmark: @@ -32,3 +34,13 @@ def partition(alist, first, last): alist2 = [1] quickSort(alist2) print(alist2) + + +if __name__ == "__main__": + test_data = [3,2,111,3,-1,0,0,1,0,2,4] + + res_stable = sorted(test_data) + quickSort(test_data) + print(test_data) + print(res_stable) + assert all(map(lambda x: x[0] == x[1], zip(res_stable, test_data))) \ No newline at end of file