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34. Find First and Last Position of Element in Sorted Arrayclass Solution(object): def searchRange(self, nums, target): """ :type nums: List[int] :type target: int ...

29. Divide Two Integersclass Solution(object): def divide(self, dividend, divisor): """ :type dividend: int :type divisor: int :rtype: int """ if (...

486. Predict the Winner[375]. Guess Number Higherclass Solution(object): def getMoneyAmount(self, n): """ :type n: int :rtype: int """ dp=[[0 for i in r...

204. Count Primesclass Solution(object): def countPrimes(self, n): """ :type n: int :rtype: int """ if n<3: return 0 prime...

300. Longest Increasing SubsequenceGiven an unsorted array of integers, find the length of longest increasing subsequence.Example:Input: [10,9,2,5,3,7,101,18]Output: 4Explanation: The longest inc...

比较tricky的解法，不用额外的内存首先考虑将二叉树转换成双向链表[LeetCode] 426. Convert Binary Search Tree to Sorted Doubly Linked List将二叉搜索树转为有序双向链表然后通过查找链表中间节点的方法找到中位数def doubleconvert(root): if not root: return None ...

# -*- coding: UTF-8 -*-class TreeNode(object): def __init__(self,val,nex): self.val=val self.next=nexdef linksort(s,e): if s==e: return key=s.val p=s ...

775. Global and Local InversionsWe have some permutation A of [0, 1, …, N - 1], where N is the length of A.The number of (global) inversions is the number of i < j with 0 <= i < j < N an...

这类题一般有个前提：Given an array of integers, 1 ≤ a[i] ≤ n (n = size of array)442. Find All Duplicates in an Arrayclass Solution(object): def findDuplicates(self, nums): """ :type num...

721. Accounts Mergeclass Solution(object): def accountsMerge(self, accounts): def find(a): if ds[a] < 0: return a ds[a] = find(ds[a]) ...

My solution:mark: not work# Definition for singly-linked list.# class ListNode(object):# def __init__(self, x):# self.val = x# self.next = Noneclass Solution(object): d...

permutation77. Combinationsclass Solution(object): def combine(self, n, k): """ :type n: int :type k: int :rtype: List[List[int]] """ def backtra...

234. Palindrome Linked Listrecursion not work, stack will be overflowclass Solution(object): def isPalindrome(self, head): """ :type head: ListNode :rtype: bool "...

91.Decode Waysdfs way:class Solution(object): def numDecodings(self, s): """ :type s: str :rtype: int """ out=[] self.ret=0 def h...

781. Rabbit in the forrest## @lc app=leetcode id=781 lang=python## [781] Rabbits in Forest#class Solution(object): def numRabbits(self, answers): """ :type answers: List[int]...

143. Reorder Listlink list ⇒ listclass Solution(object): def reorderList(self, head): """ :type head: ListNode :rtype: None Do not return anything, modify head in-place i...

[572] Subtree of Another Treeclass Solution(object): def isSubtree(self, s, t): """ :type s: TreeNode :type t: TreeNode :rtype: bool """ if not s ...

743. Network Delay TimeInput: times = [[2,1,1],[2,3,1],[3,4,1]], N = 4, K = 2Output: 2class Solution(object): def networkDelayTime(self, times, N, K): """ :type times: List[Lis...

class Solution: def helper(self,s,l,r): while l>=0 and r<len(s) and s[l]==s[r]: l=l-1 r=r+1 return s[l+1:r] def longestPalindrome(self, s...

数组按出现频次从大到小排序http://www.geeksforgeeks.org/amazon-interview-set-21/#include &amp;amp;amp;amp;amp;amp;amp;amp;lt;stdio.h&amp;amp;amp;amp;amp;amp;amp;amp;gt;typedef struct{int id;int count;}item;void sort(int a[], int n){item temp[n];

Given a string, sort it in decreasing order based on the frequency of characters.Example 1:Input:“tree”Output:“eert”Explanation:‘e’ appears twice while ‘r’ and ‘t’ both appear once.So ‘e’ must...

Given an array of integers, every element appears twice except for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra m...

Given two strings s and t which consist of only lowercase letters.String t is generated by random shuffling string s and then add one more letter at a random position.Find the letter that was added ...

Write a function that takes a string as input and returns the string reversed.Example:Given s = “hello”, return “olleh”.void inverse(int start, int end, char *p){ char temp; if(p) { temp=p[st...

增加一個pre 和next 節點進行鏈表内部的翻轉# Definition for singly-linked list.# class ListNode(object):# def __init__(self, x):# self.val = x# self.next = Noneclass Solution(object): def...

Tag: Dictclass Solution(object): def twoSum(self, nums, target): """ :type nums: List[int] :type target: int :rtype: List[int] """ dic={} r...

Leetcode[2] Add Two Numbersclass Solution(object): def addTwoNumbers(self, l1, l2): """ :type l1: ListNode :type l2: ListNode :rtype: ListNode """ ...

本质上是一样的解决方案，利用python的heapq 进行解题[347] Top K Frequent Elementsclass Solution(object): def topKFrequent(self, nums, k): """ :type nums: List[int] :type k: int :rtype...

4 keyboardclass Solution {public: int maxA(int N) { vector<int> dp(N + 1, 0); for (int i = 0; i <= N; ++i) { dp[i] = i; for (int j = 1; j < i ...

[322] coin changeclass Solution(object): def coinChange(self, coins, amount): """ :type coins: List[int] :type amount: int :rtype: int """ #init as...

Take or Skip problem740. Delete and Earnclass Solution(object): def deleteAndEarn(self, nums): """ :type nums: List[int] :rtype: int """ dp=[0 for i in ra...

42. Trapping Rain Waterclass Solution(object): def trap(self, height): """ :type height: List[int] :rtype: int """ st=[] #use decrease stack here ...

[264] Ugly Number IIclass Solution(object): def nthUglyNumber(self, n): """ :type n: int :rtype: int """ if n<=0: return 0 if n==1:...

an error:keyerror,class Solution(object): def copyRandomList(self, head): """ :type head: Node :rtype: Node """ if head==None: return None ...