124. Binary Tree Maximum Path Sum

Description Given a non-empty binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tre...

2019/04/18 11:53
57
262. Trips and Users

Description Difficulty: Hard Tag: Sql The Trips table holds all taxi trips. Each trip has a unique Id, while Client_Id and Driver_Id are both foreign keys to the Users_Id at the...

2019/01/04 18:15
32
739. Daily Temperatures

Description Tag：Stack, Hash Table Difficulty: Medium Given a list of daily temperatures T, return a list such that, for each day in the input, tells you how many days you woul...

2018/11/26 20:54
101
453. Minimum Moves to Equal Array Elements

Description Given a non-empty integer array of size n, find the minimum number of moves required to make all array elements equal, where a move is incrementing n - 1 elements by...

2018/11/23 20:32
68
430. Flatten a Multilevel Doubly Linked List

Description Difficulty: Medium Tag: LinkedList, DFS You are given a doubly linked list which in addition to the next and previous pointers, it could have a child pointer, which ...

2018/11/10 18:34
206
57. Insert Interval

Description Difficulty： Hard Tag： Array Sort Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary). You may assume that the ...

2018/11/03 15:46
52
868. Binary Gap

Description Difficulty：Easy Tag： Math Given a positive integer N, find and return the longest distance between two consecutive 1's in the binary representation of N. If there ...

2018/11/03 14:51
117
284. Peeking Iterator

Description Tag： Design Difficulties： Medium Given an Iterator class interface with methods: next() and hasNext(), design and implement a PeekingIterator that support the pee...

2018/10/21 22:25
55
457. Circular Array Loop

Description Difficulty : Medium You are given an array of positive and negative integers. If a number n at an index is positive, then move forward n steps. Conversely, if it's n...

2018/10/19 20:42
165
403. Frog Jump

Description Tag：Dynamic Programming Difficulty：Hard A frog is crossing a river. The river is divided into x units and at each unit there may or may not exist a stone. The fro...

2018/10/19 11:21
56
76. Minimum Window Substring

Description tags: Hash Table, Two Pointers, String difficulty: Hard Given a string S and a string T, find the minimum window in S which will contain all the characters in T in c...

2018/10/18 16:06
33
735. Asteroid Collision

Description tags: Stack difficulty: medium We are given an array asteroids of integers representing asteroids in a row. For each asteroid, the absolute value represents its size...

2018/10/12 11:10
41
40. Combination Sum II

Description tag: array , backtraking difficulty : medium Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candi...

2018/10/11 16:08
26
39. Combination Sum

Description tags : array, backtracking difficulty: medium Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combin...

2018/10/11 14:56
23
37. Sudoku Solver

Description tags: backtrack,hash table difficulty: hard Write a program to solve a Sudoku puzzle by filling the empty cells. A sudoku solution must satisfy all of the following ...

2018/09/26 19:01
41
30. Substring with Concatenation of All Words

Description tag: Hash Table, Two Pointers, String difficulty: Hard You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indi...

2018/09/26 19:01
26
LeetCode53-Maximum Subarray

Description tags : Divide And Conquer Dynamic Programming Array Difficulties ： easy Given an integer array nums, find the contiguous subarray (containing at least one number) ...

2018/09/02 18:13
98
LeetCode24-Swap Nodes in Pairs

Description Given a linked list, swap every two adjacent nodes and return its head. Example: Given 1->2->3->4, you should return the list as 2->1->4->3. Note: Your algorithm sho...

2018/08/11 18:24
21
LeetCode23-Merge k Sorted Lists

Description Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. Example: Input: [ 1->4->5, 1->3->4, 2->6 ] Output: 1->1->2->3->4->...

2018/08/01 19:35
8
LeetCode22- Generate Parentheses

Description Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. For example, given n = 3, a solution set is: [ "((()))", "(()...

2018/08/01 18:34
30