leetcode

[LeetCode-interview algorithm classic-Java implementation] [077-Combinations (number of Combinations)], leetcode -- java [077-Combinations (number of Combinations )][LeetCode-interview algorithm classic-Java implementation] [directory indexes for all questions]Original question Given two integers n and k, return all possible combinations of k numbers out of 1...

[LeetCode-interview algorithm classic-Java implementation] [029-Divide Two Integers (Division of Two Integers)], leetcode -- java [029-Divide Two Integers (Division of Two Integers )][LeetCode-interview algorithm classic-Java implementation] [directory indexes for all questions]Original question Divide two integers without using multiplication, division and mod o

[LeetCode-interview algorithm classic-Java implementation] [024-Swap Nodes in Pairs (node of the paired exchange single-chain table)], leetcode -- java [024-Swap Nodes in Pairs (node of the paired exchange single-chain table )][LeetCode-interview algorithm classic-Java implementation] [directory indexes for all questions]Original question Given a linked list, swa

[LeetCode-interview algorithm classic-Java implementation] [063-Unique Paths II (Unique path Question II)], leetcode -- java [063-Unique Paths II (Unique path Problem II )][LeetCode-interview algorithm classic-Java implementation] [directory indexes for all questions]Original question Follow up for "Unique Paths ":Now consider if some obstacles are added to the g

[LeetCode-interview algorithm classic-Java implementation] [057-Insert Interval (Insert Interval)], leetcode -- java [057-Insert Interval (Insert Interval )][LeetCode-interview algorithm classic-Java implementation] [directory indexes for all questions]Original question Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if n

[LeetCode-interview algorithm classic-Java implementation] [215-Kth Largest Element in an Array (number of K in the Array)], leetcode -- java [215-Kth Largest Element in an Array (number of K in the Array )][LeetCode-interview algorithm classic-Java implementation] [directory indexes for all questions]Download the Code [https://github.com/wang-jun-chao]Original q

[LeetCode-interview algorithm classic-Java implementation] [217-Contains Duplicate (including Duplicate elements)], leetcode -- java [217-Contains Duplicate (including Duplicate elements )][LeetCode-interview algorithm classic-Java implementation] [directory indexes for all questions]Download the Code [https://github.com/wang-jun-chao]Original question Given an a

[LeetCode-interview algorithm classic-Java implementation] [100-Same Tree (whether the two sides are the Same)], leetcode -- java [100-Same Tree (whether the two trees are the Same )][LeetCode-interview algorithm classic-Java implementation] [directory indexes for all questions]Original question Given two binary trees, write a function to check if they are equal

[LeetCode-interview algorithm classic-Java implementation] [066-Plus One (add One)], leetcode -- java [066-Plus One (Plus One )][LeetCode-interview algorithm classic-Java implementation] [directory indexes for all questions]Original question Given a non-negative number represented as an array of digits, plus one to the number.The digits are stored such that the m

Leetcode Note: 3Sum, leetcode note 3sum I. Description Ii. problem-solving skills This question is similar to the Two Sum of another question. However, this question is used to search for three numbers in the array so that the Sum is 0. At the same time, it is required that the three numbers only appear once. If we only need to use the brute force algorithm, the time complexity is O (n ^ 3), and it is dif

Leetcode 17 Letter Combinations of a Phone Number, leetcode Given a digit string, return all possible letter combinations that the number coshould represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23"Output: ["ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf"]. Cycle: Enter the number of digits {each character string consisting of the previo

LeetCode-Distinct Subsequences, leetcode-distinct Title: https://oj.leetcode.com/problems/distinct-subsequences/ Given a string S and a string T, count the number of distinct subsequences of T in S. A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (ie,"AC

LeetCode Rising Temperature, leetcode GivenWeatherTable, write a SQL query to find all dates 'IDs with higher temperature compared to its previous (yesterday's) dates. + --------- + ------------ + ---------------- + | Id (INT) | Date (DATE) | Temperature (INT) | + --------- + ------------ + ---------------- + | 1 | 2015-01-01 | 10 | 2 | 2015-01-02 | 25 | 3 | 2015-01-03 | 20 | 4 | 2015-01-04 | 30 | + ---

[LeetCode] DeleteDuplicateEmails, solution report, leetcode Question SQL query to delete all duplicate email entries in a table named Person, keeping only unique emails based on its smallest Id. Id Email 1 John@example.com 2 Bob@example.com 3 John@example.com Id is the primary key column for this table.For example, after running your query, t

LeetCode Substring with Concatenation of All Words, leetcode You are given a string, S, and a list of words, L, that are all of the same length. find all starting indices of substring (s) in S that is a concatenation of each word in L exactly once and without any intervening characters. For example, given:S:"barfoothefoobarman"L:["foo", "bar"] You shoshould return the indices:[0,9].(Order does not matter )

[LeetCode-interview algorithm classic-Java implementation] [001-Two Sum (Sum of Two numbers)], leetcode -- java [001-Two Sum (calculate the Sum of Two numbers )]Original question Given an array of integers, find two numbers such that they add up to a specific target number.The function twoSum shocould return indices of the two numbers such that they add up to the target, where index1 must be less than index

Leetcode=-- Basic Calculator, leetcode Implement a basic calculator to evaluate a simple expression string. The expression string may contain open(And closing parentheses), The plus+Or minus sign-, Non-negative integers and empty spaces. You may assume that the given expression is always valid. Some examples: "1 + 1" = 2" 2-1 + 2 " = 3"(1+(4+5+2)-3)+(6+8)" = 23 Note: Do not useevalBuilt-in library function

LeetCode-Atoi, leetcode Implement atoi to convert a string to an integer. There are already many solutions available on the Internet. Here we mainly pay attention to some points (the most important thing is that the returned value should be assigned a value of long at the beginning because it may cross the border) Then there are some special situations for analysis. Class Solution {public: int atoi (strin

LeetCode Best Time to Buy and other Stock II, leetcode= Best Time to Buy and Buy Stock II Total Accepted: 41127 Total Submissions: 108434 My Submissions Question SolutionSay you have an array for which the ith element is the price of a given stock on day I. Design an algorithm to find the maximum profit. you may complete as your transactions as you like (ie, buy one and every one share of the stock multipl

Leetcode exercise notes and leetcode exercises Start with the basic questions, write each question by category, and record questions and gains. 1. Two Sum Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input wocould haveExactlyOne solution, and you may not useSameElement twice. Example: Given nums = [2, 7, 11, 15], target =