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371 | today we're gonna working on net code question number 371 uh sum of two integers uh you have been given two integers a and b return the sum of two integers without using the uh operators uh plus or negative sign so we just have to sum two numbers and we're gonna run the result so we're gonna be using uh doing the bit m... | Sum of Two Integers | sum-of-two-integers | Given two integers `a` and `b`, return _the sum of the two integers without using the operators_ `+` _and_ `-`.
**Example 1:**
**Input:** a = 1, b = 2
**Output:** 3
**Example 2:**
**Input:** a = 2, b = 3
**Output:** 5
**Constraints:**
* `-1000 <= a, b <= 1000` | null | Math,Bit Manipulation | Medium | 2 |
494 | hey what's up guys john here again and today let's take a look at another lead called problem here uh number 494 target some another medium problem okay so let's see what's the problem is asking us to do here you're given like a list of negative integers right it's either zero or positive integers and the target as now... | Target Sum | target-sum | You are given an integer array `nums` and an integer `target`.
You want to build an **expression** out of nums by adding one of the symbols `'+'` and `'-'` before each integer in nums and then concatenate all the integers.
* For example, if `nums = [2, 1]`, you can add a `'+'` before `2` and a `'-'` before `1` and ... | null | Array,Dynamic Programming,Backtracking | Medium | 282 |
797 | Anatolia gram problem in this series and it was a great benefit like a boss I think she is a [ __ ] was a great benefit like a boss I think she is a [ __ ] was a great benefit like a boss I think she is a [ __ ] Talip Emre trust everywhere But this is the last grow to women liquid my first conscience rubber Studio with... | All Paths From Source to Target | rabbits-in-forest | Given a directed acyclic graph (**DAG**) of `n` nodes labeled from `0` to `n - 1`, find all possible paths from node `0` to node `n - 1` and return them in **any order**.
The graph is given as follows: `graph[i]` is a list of all nodes you can visit from node `i` (i.e., there is a directed edge from node `i` to node `... | null | Array,Hash Table,Math,Greedy | Medium | null |
745 | hi guys this is khushboo and welcome to algorithms made easy in this video we will see the question prefix and suffix search given a special dictionary which has some words and allow you to search the words in it by a prefix and a suffix implement the word filter class wherein the word filter constructor initializes th... | Prefix and Suffix Search | find-smallest-letter-greater-than-target | Design a special dictionary that searches the words in it by a prefix and a suffix.
Implement the `WordFilter` class:
* `WordFilter(string[] words)` Initializes the object with the `words` in the dictionary.
* `f(string pref, string suff)` Returns _the index of the word in the dictionary,_ which has the prefix `p... | Try to find whether each of 26 next letters are in the given string array. | Array,Binary Search | Easy | 2269 |
717 | all right so let's talk about one b and two big characters so we have this two spatial characters so the first character can be represented by one bit zero and the secondary one can be represented by two b one zero or one right so how do you actually solve it so this question is really tricky and you could be done but ... | 1-bit and 2-bit Characters | 1-bit-and-2-bit-characters | We have two special characters:
* The first character can be represented by one bit `0`.
* The second character can be represented by two bits (`10` or `11`).
Given a binary array `bits` that ends with `0`, return `true` if the last character must be a one-bit character.
**Example 1:**
**Input:** bits = \[1,0,0... | Keep track of where the next character starts. At the end, you want to know if you started on the last bit. | Array | Easy | 89 |
630 | welcome to mazelico challenge today's problem is course schedule three there are n different online courses numbered from one to n you are given an array courses where courses i has two items duration last day this indicates that the ith course should be taken continuously for the duration of days first item and must b... | Course Schedule III | course-schedule-iii | There are `n` different online courses numbered from `1` to `n`. You are given an array `courses` where `courses[i] = [durationi, lastDayi]` indicate that the `ith` course should be taken **continuously** for `durationi` days and must be finished before or on `lastDayi`.
You will start on the `1st` day and you cannot ... | During iteration, say I want to add the current course, currentTotalTime being total time of all courses taken till now, but adding the current course might exceed my deadline or it doesn’t.
1. If it doesn’t, then I have added one new course. Increment the currentTotalTime with duration of current course. 2. If it e... | Array,Greedy,Heap (Priority Queue) | Hard | 207,210,2176 |
257 | okay so we have another one of the lead code problem so let's go ahead and uh check the question so it's our lead code 257. so it's a binary tree path uh so basically given the root of a binary tree uh return all route to leave path in any order alif is a node with no children so this is what we have so basically uh if... | Binary Tree Paths | binary-tree-paths | Given the `root` of a binary tree, return _all root-to-leaf paths in **any order**_.
A **leaf** is a node with no children.
**Example 1:**
**Input:** root = \[1,2,3,null,5\]
**Output:** \[ "1->2->5 ", "1->3 "\]
**Example 2:**
**Input:** root = \[1\]
**Output:** \[ "1 "\]
**Constraints:**
* The number of nodes ... | null | String,Backtracking,Tree,Depth-First Search,Binary Tree | Easy | 113,1030,2217 |
215 | hey what's up guys this is chung so this time number 215 k largest element in an array so this is one of the classic problem you know basically you're given you need to find the case largest element in the unsorted array so note that this is the case largest element in this sorted order not the case distinct number so ... | Kth Largest Element in an Array | kth-largest-element-in-an-array | Given an integer array `nums` and an integer `k`, return _the_ `kth` _largest element in the array_.
Note that it is the `kth` largest element in the sorted order, not the `kth` distinct element.
You must solve it in `O(n)` time complexity.
**Example 1:**
**Input:** nums = \[3,2,1,5,6,4\], k = 2
**Output:** 5
**Ex... | null | Array,Divide and Conquer,Sorting,Heap (Priority Queue),Quickselect | Medium | 324,347,414,789,1014,2113,2204,2250 |
515 | hello everyone let's try to be a cheat code ninja today in this problem we are given a binary tree and we have to return the largest values in each row of this tree let's understand this with the help of an example in this binary tree we have three rows in the first row we have only one node and the maximum value is on... | Find Largest Value in Each Tree Row | find-largest-value-in-each-tree-row | Given the `root` of a binary tree, return _an array of the largest value in each row_ of the tree **(0-indexed)**.
**Example 1:**
**Input:** root = \[1,3,2,5,3,null,9\]
**Output:** \[1,3,9\]
**Example 2:**
**Input:** root = \[1,2,3\]
**Output:** \[1,3\]
**Constraints:**
* The number of nodes in the tree will be... | null | Tree,Depth-First Search,Breadth-First Search,Binary Tree | Medium | null |
295 | hello everyone let's solve today's lead code question find median from data stream today's question is to implement a design problem the main feature to implement is to calculate the median value in an ordered integer list if you have an odd number of elements then we need to select the middle value in an ordered array... | Find Median from Data Stream | find-median-from-data-stream | The **median** is the middle value in an ordered integer list. If the size of the list is even, there is no middle value, and the median is the mean of the two middle values.
* For example, for `arr = [2,3,4]`, the median is `3`.
* For example, for `arr = [2,3]`, the median is `(2 + 3) / 2 = 2.5`.
Implement the M... | null | Two Pointers,Design,Sorting,Heap (Priority Queue),Data Stream | Hard | 480,1953,2207 |
100 | hey and welcome today we are going to solve same tree interview question we will walk through both BFS and DFS solutions for this so let's get into it first example here we have two sub trees and every single node of them has the same value and placed in the same subt Tree location we have one as rot two in the left an... | Same Tree | same-tree | Given the roots of two binary trees `p` and `q`, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical, and the nodes have the same value.
**Example 1:**
**Input:** p = \[1,2,3\], q = \[1,2,3\]
**Output:** true
**Example 2:**
**Input:** p... | null | Tree,Depth-First Search,Breadth-First Search,Binary Tree | Easy | null |
896 | here we go satellite radio what's up guys Nick white here I did talking stuff on twitching you to check the description for all my information join the discord everyone's in there talking about stuff we got referral sheets and all this crap and you guys I make all these videos doesn't seem like you like it so please li... | Monotonic Array | smallest-subtree-with-all-the-deepest-nodes | An array is **monotonic** if it is either monotone increasing or monotone decreasing.
An array `nums` is monotone increasing if for all `i <= j`, `nums[i] <= nums[j]`. An array `nums` is monotone decreasing if for all `i <= j`, `nums[i] >= nums[j]`.
Given an integer array `nums`, return `true` _if the given array is ... | null | Hash Table,Tree,Depth-First Search,Breadth-First Search,Binary Tree | Medium | null |
1 | hey guys persistent programmer here and welcome back to my channel so in this channel we solve a lot of algorithms and go over legal questions so if you haven't subscribed already go ahead and hit the subscribe button smash that like button because that helps me create this content for you guys so without further ado l... | Two Sum | two-sum | Given an array of integers `nums` and an integer `target`, return _indices of the two numbers such that they add up to `target`_.
You may assume that each input would have **_exactly_ one solution**, and you may not use the _same_ element twice.
You can return the answer in any order.
**Example 1:**
**Input:** nums... | A really brute force way would be to search for all possible pairs of numbers but that would be too slow. Again, it's best to try out brute force solutions for just for completeness. It is from these brute force solutions that you can come up with optimizations. So, if we fix one of the numbers, say x, we have to scan ... | Array,Hash Table | Easy | 15,18,167,170,560,653,1083,1798,1830,2116,2133,2320 |
539 | hi guys this is Akshay and today we will be discussing an algorithm problem that was asked to me in one of the rounds at Google so here is the problem given a list of 24 hour clock time points in hhmm format return the minimum minutes difference between any two time points in the list the examples um are 2359 and 0. so... | Minimum Time Difference | minimum-time-difference | Given a list of 24-hour clock time points in **"HH:MM "** format, return _the minimum **minutes** difference between any two time-points in the list_.
**Example 1:**
**Input:** timePoints = \["23:59","00:00"\]
**Output:** 1
**Example 2:**
**Input:** timePoints = \["00:00","23:59","00:00"\]
**Output:** 0
**Constrai... | null | Array,Math,String,Sorting | Medium | 2266 |
349 | hello guys welcome back to my YouTube channel today I'm going to solve day 10 problem of this month on lead Cod before starting if you guys haven't subscribed my YouTube channel yet then please go ahead and subscribe it now let's read the problem statement so today uh we are going to solve problem number 349 that is in... | Intersection of Two Arrays | intersection-of-two-arrays | Given two integer arrays `nums1` and `nums2`, return _an array of their intersection_. Each element in the result must be **unique** and you may return the result in **any order**.
**Example 1:**
**Input:** nums1 = \[1,2,2,1\], nums2 = \[2,2\]
**Output:** \[2\]
**Example 2:**
**Input:** nums1 = \[4,9,5\], nums2 = \... | null | Array,Hash Table,Two Pointers,Binary Search,Sorting | Easy | 350,1149,1392,2190,2282 |
134 | Hello friends, today's question is gas station. This is a medium level question of eklith court. In this question, we will be given two expectations, first will be gas and second will be cost, so there will be a circular route inside which there will be gas station plants. We will be given any gas. We can start from th... | Gas Station | gas-station | There are `n` gas stations along a circular route, where the amount of gas at the `ith` station is `gas[i]`.
You have a car with an unlimited gas tank and it costs `cost[i]` of gas to travel from the `ith` station to its next `(i + 1)th` station. You begin the journey with an empty tank at one of the gas stations.
Gi... | null | Array,Greedy | Medium | 1346 |
209 | you guys as we've been doing this is chaser in this video I'm going to try to solve 209 minimum size of ERISA we're given a rate of M positive leaders and a positive in GS find the minimum then minimum length of contiguous sub-array minimum length of contiguous sub-array minimum length of contiguous sub-array which the... | Minimum Size Subarray Sum | minimum-size-subarray-sum | Given an array of positive integers `nums` and a positive integer `target`, return _the **minimal length** of a_ _subarray_ _whose sum is greater than or equal to_ `target`. If there is no such subarray, return `0` instead.
**Example 1:**
**Input:** target = 7, nums = \[2,3,1,2,4,3\]
**Output:** 2
**Explanation:** Th... | null | Array,Binary Search,Sliding Window,Prefix Sum | Medium | 76,325,718,1776,2211,2329 |
63 | Yes, hello, this is Gary Niel, a developer child. The problem we will solve today is number 63, Unique Pass Two. There is a robot in the upper left corner. The robot can only move down or to the right. This robot has a separate mark in the lower right corner. The goal is to reach the desired destination. It is a matter... | Unique Paths II | unique-paths-ii | You are given an `m x n` integer array `grid`. There is a robot initially located at the **top-left corner** (i.e., `grid[0][0]`). The robot tries to move to the **bottom-right corner** (i.e., `grid[m - 1][n - 1]`). The robot can only move either down or right at any point in time.
An obstacle and space are marked as ... | The robot can only move either down or right. Hence any cell in the first row can only be reached from the cell left to it. However, if any cell has an obstacle, you don't let that cell contribute to any path. So, for the first row, the number of ways will simply be
if obstacleGrid[i][j] is not an obstacle
... | Array,Dynamic Programming,Matrix | Medium | 62,1022 |
84 | Hello friends welcome back today we are solving largest rectangle in histogram problem first we'll start with reading the problem statement and then we'll look at some examples next we'll discuss the Brute Force approach to solve this problem that has the runtime of ofn Cube and we'll optimize this Brute Force approach... | Largest Rectangle in Histogram | largest-rectangle-in-histogram | Given an array of integers `heights` representing the histogram's bar height where the width of each bar is `1`, return _the area of the largest rectangle in the histogram_.
**Example 1:**
**Input:** heights = \[2,1,5,6,2,3\]
**Output:** 10
**Explanation:** The above is a histogram where width of each bar is 1.
The l... | null | Array,Stack,Monotonic Stack | Hard | 85,1918 |
386 | hey guys today we will be solving a problem called lexicographical numbers it says given an integer n return all the numbers in the range of one n inclusive sorted in let's say order is the same order that you guys see in a dictionary and for numbers it would be the smallest number comes first and uh if this first numb... | Lexicographical Numbers | lexicographical-numbers | Given an integer `n`, return all the numbers in the range `[1, n]` sorted in lexicographical order.
You must write an algorithm that runs in `O(n)` time and uses `O(1)` extra space.
**Example 1:**
**Input:** n = 13
**Output:** \[1,10,11,12,13,2,3,4,5,6,7,8,9\]
**Example 2:**
**Input:** n = 2
**Output:** \[1,2\]
*... | null | Depth-First Search,Trie | Medium | null |
497 | hey guys this is Dean uh I'll be covering all the questions from the earth 30 days challenge playlist and this questions uh this question consist of uh 100 to 90 questions of from top six companies like Google Microsoft Goldman Shacks Amazon and different companies uh so I'll be covering all these questions I'll be tal... | Random Point in Non-overlapping Rectangles | random-point-in-non-overlapping-rectangles | You are given an array of non-overlapping axis-aligned rectangles `rects` where `rects[i] = [ai, bi, xi, yi]` indicates that `(ai, bi)` is the bottom-left corner point of the `ith` rectangle and `(xi, yi)` is the top-right corner point of the `ith` rectangle. Design an algorithm to pick a random integer point inside th... | null | null | Medium | null |
109 | hi everyone in this video we are going to solve a problem the problem name is convert sorted list to Binary and the pro number is 109 all right so guys first of all we are going to clearly understand what this problem says after that we are going to move to the logic part and after that we're going to implement our log... | Convert Sorted List to Binary Search Tree | convert-sorted-list-to-binary-search-tree | Given the `head` of a singly linked list where elements are sorted in **ascending order**, convert _it to a_ **_height-balanced_** _binary search tree_.
**Example 1:**
**Input:** head = \[-10,-3,0,5,9\]
**Output:** \[0,-3,9,-10,null,5\]
**Explanation:** One possible answer is \[0,-3,9,-10,null,5\], which represents t... | null | Linked List,Divide and Conquer,Tree,Binary Search Tree,Binary Tree | Medium | 108,2306 |
86 | hello friends in this session we are going to discuss about another lead code problem partition list lead code labeled it as medium but this is pretty simple problem let's understand the problem statement you will be given a linked list as input and another input variable x we need to partition this linked list in such... | Partition List | partition-list | Given the `head` of a linked list and a value `x`, partition it such that all nodes **less than** `x` come before nodes **greater than or equal** to `x`.
You should **preserve** the original relative order of the nodes in each of the two partitions.
**Example 1:**
**Input:** head = \[1,4,3,2,5,2\], x = 3
**Output:**... | null | Linked List,Two Pointers | Medium | 2265 |
198 | hey what's up guys John here again so this time I'd like to talk about this problem a least called the problem 198 house rubber and today what it's easy I think it's kind of easy between easy and medium because this we'll be using because we'll be using a dynamic programming idea here even though it's a 1d dynamic prog... | House Robber | house-robber | You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of them is that adjacent houses have security systems connected and **it will automatically contact the police if two adjacent houses were broken into... | null | Array,Dynamic Programming | Medium | 152,213,256,276,337,600,656,740,2262 |
67 | in this problem we have to perform binary addition we are given two strings and both are containing digits which are either 0 or 1 so this is not a simple string it represents a number in binary form so for example if you add 5 and 2 actually you are adding 1 0 1 its binary representation and the representation for 2 i... | Add Binary | add-binary | Given two binary strings `a` and `b`, return _their sum as a binary string_.
**Example 1:**
**Input:** a = "11", b = "1"
**Output:** "100"
**Example 2:**
**Input:** a = "1010", b = "1011"
**Output:** "10101"
**Constraints:**
* `1 <= a.length, b.length <= 104`
* `a` and `b` consist only of `'0'` or `'1'` chara... | null | Math,String,Bit Manipulation,Simulation | Easy | 2,43,66,1031 |
1,964 | hey everybody this is Larry this is day seven of the medical day challenge hit the like button hit the Subscribe button join me on Discord let me know what you think about today's poem and why do they move afterwards also oh no that's tomorrow so tomorrow will be the weekly film and today's problem is 1964 find the lon... | Find the Longest Valid Obstacle Course at Each Position | find-interview-candidates | You want to build some obstacle courses. You are given a **0-indexed** integer array `obstacles` of length `n`, where `obstacles[i]` describes the height of the `ith` obstacle.
For every index `i` between `0` and `n - 1` (**inclusive**), find the length of the **longest obstacle course** in `obstacles` such that:
* ... | null | Database | Medium | null |
1,202 | That hey guys welcome and welcome back to my channel english video we are going to solve smaller system with wax swiss problem mein kya hai ki aapke ek string gas de raha hai aur 1 and a half years of india is late akhar ok what should we do What we have to do is swap whatever elements we have given in this license and... | Smallest String With Swaps | palindrome-removal | You are given a string `s`, and an array of pairs of indices in the string `pairs` where `pairs[i] = [a, b]` indicates 2 indices(0-indexed) of the string.
You can swap the characters at any pair of indices in the given `pairs` **any number of times**.
Return the lexicographically smallest string that `s` can be chang... | Use dynamic programming. Let dp[i][j] be the solution for the sub-array from index i to index j. Notice that if we have S[i] == S[j] one transition could be just dp(i + 1, j + 1) because in the last turn we would have a palindrome and we can extend this palindrome from both sides, the other transitions are not too diff... | Array,Dynamic Programming | Hard | null |
1,536 | uh hey everybody this is larry this is me solving q3 of the recent contest minimum swaps to arrange a binary grid um so this is actually kind of a tricky problem for me to actually understand just reading the problem right but the key observation for this problem though is just knowing that uh the only thing that matte... | Minimum Swaps to Arrange a Binary Grid | customers-who-bought-products-a-and-b-but-not-c | Given an `n x n` binary `grid`, in one step you can choose two **adjacent rows** of the grid and swap them.
A grid is said to be **valid** if all the cells above the main diagonal are **zeros**.
Return _the minimum number of steps_ needed to make the grid valid, or **\-1** if the grid cannot be valid.
The main diago... | null | Database | Medium | null |
209 | hello and welcome to another CS tutor Center video today we're going to talk about the leak code problem minimum size subay sum so let's get started first what we'll do is we're going to read this description and we're going to look for keywords that tip us off as to what coding pattern we can use and then when we have... | Minimum Size Subarray Sum | minimum-size-subarray-sum | Given an array of positive integers `nums` and a positive integer `target`, return _the **minimal length** of a_ _subarray_ _whose sum is greater than or equal to_ `target`. If there is no such subarray, return `0` instead.
**Example 1:**
**Input:** target = 7, nums = \[2,3,1,2,4,3\]
**Output:** 2
**Explanation:** Th... | null | Array,Binary Search,Sliding Window,Prefix Sum | Medium | 76,325,718,1776,2211,2329 |
149 | imagine that you have a set of 2d points and you want to find the line that passes from the most points that's what the max points on a line problem about we have a list of 2d points and we want to find the maximum number of points that lie on the same line in the example below it's 5 because we have a line that passes... | Max Points on a Line | max-points-on-a-line | Given an array of `points` where `points[i] = [xi, yi]` represents a point on the **X-Y** plane, return _the maximum number of points that lie on the same straight line_.
**Example 1:**
**Input:** points = \[\[1,1\],\[2,2\],\[3,3\]\]
**Output:** 3
**Example 2:**
**Input:** points = \[\[1,1\],\[3,2\],\[5,3\],\[4,1\]... | null | Array,Hash Table,Math,Geometry | Hard | 356,2287 |
1,011 | hello everyone so let's solve the problem capacity to ship packages within D days what is the problem saying a conveyor belt has packages that must be shipped from one port to another within days all right the ith package on the conveyor belt has a weight of this each day we load the ship with packages on the conveyor ... | Capacity To Ship Packages Within D Days | flip-binary-tree-to-match-preorder-traversal | A conveyor belt has packages that must be shipped from one port to another within `days` days.
The `ith` package on the conveyor belt has a weight of `weights[i]`. Each day, we load the ship with packages on the conveyor belt (in the order given by `weights`). We may not load more weight than the maximum weight capaci... | null | Tree,Depth-First Search,Binary Tree | Medium | null |
202 | Hello hello friends in this section they want to discuss about this simple step is p number of the record interview will give you need to avoid happy number and unit replace subscribe and liquid in which results in subscribe next video subscribe are equal to 100 will Repeat Interactive Virval Two 9 Science Chapter Numb... | Happy Number | happy-number | Write an algorithm to determine if a number `n` is happy.
A **happy number** is a number defined by the following process:
* Starting with any positive integer, replace the number by the sum of the squares of its digits.
* Repeat the process until the number equals 1 (where it will stay), or it **loops endlessly ... | null | Hash Table,Math,Two Pointers | Easy | 141,258,263,2076 |
39 | welcome to october's leeco challenge today's problem is combination sum given an array of distinct integers and a target integer return a list of all unique combinations where the chosen number sum chosen numbers sum to target you may return the combinations in any order the same number may be chosen from candidates on... | Combination Sum | combination-sum | Given an array of **distinct** integers `candidates` and a target integer `target`, return _a list of all **unique combinations** of_ `candidates` _where the chosen numbers sum to_ `target`_._ You may return the combinations in **any order**.
The **same** number may be chosen from `candidates` an **unlimited number of... | null | Array,Backtracking | Medium | 17,40,77,216,254,377 |
968 | hello friends today list of binary tree cameras given binary windstorm cameras on the nodes of the tree each camera at a node can monitor its parent itself and its immediate children calculate the minimum number of cameras needed to monitor all nodes of the tree let's see these two examples in the first example we only... | Binary Tree Cameras | beautiful-array | You are given the `root` of a binary tree. We install cameras on the tree nodes where each camera at a node can monitor its parent, itself, and its immediate children.
Return _the minimum number of cameras needed to monitor all nodes of the tree_.
**Example 1:**
**Input:** root = \[0,0,null,0,0\]
**Output:** 1
**Exp... | null | Array,Math,Divide and Conquer | Medium | null |
459 | so today i'm going to show you an easy way to solve this problem it's called repeated substring pattern problem uh challenge number four five nine detectors so basically what we want to do is to be dividing the string by numbers so we are going to start from um r2 we are going to divide by two and then combine these tw... | Repeated Substring Pattern | repeated-substring-pattern | Given a string `s`, check if it can be constructed by taking a substring of it and appending multiple copies of the substring together.
**Example 1:**
**Input:** s = "abab "
**Output:** true
**Explanation:** It is the substring "ab " twice.
**Example 2:**
**Input:** s = "aba "
**Output:** false
**Example 3:**
... | null | String,String Matching | Easy | 28,686 |
832 | Work in this area Ajay Ko That [ That [ That Hello Everyone and Welcome to New Video in this Video Before going to discuss another problem from code problem share and subscribe liquid liner meaning element village meaning first of all we Subscribe means to zero, subscribe means to subscribe every day, Nirodh will go to... | Flipping an Image | binary-tree-pruning | Given an `n x n` binary matrix `image`, flip the image **horizontally**, then invert it, and return _the resulting image_.
To flip an image horizontally means that each row of the image is reversed.
* For example, flipping `[1,1,0]` horizontally results in `[0,1,1]`.
To invert an image means that each `0` is repla... | null | Tree,Depth-First Search,Binary Tree | Medium | null |
1,171 | this question is you need to remove a zero sum consecutive note from linked list you can see one input and output given I'll explain you the approach how we solve this question with proper diagram first we will create a domino with value 0 next Domino next will be initialized to head node second point is I will take on... | Remove Zero Sum Consecutive Nodes from Linked List | shortest-path-in-binary-matrix | Given the `head` of a linked list, we repeatedly delete consecutive sequences of nodes that sum to `0` until there are no such sequences.
After doing so, return the head of the final linked list. You may return any such answer.
(Note that in the examples below, all sequences are serializations of `ListNode` objects.)... | Do a breadth first search to find the shortest path. | Array,Breadth-First Search,Matrix | Medium | null |
52 | hello friends welcome to joy of life so today we are going to look at the heart problem which is uh problem number 52. the problem is and queens too it's the extension of the main problem in queens um which i have done a video previously you can check it out before checking this as well i'll share the link as well in t... | N-Queens II | n-queens-ii | The **n-queens** puzzle is the problem of placing `n` queens on an `n x n` chessboard such that no two queens attack each other.
Given an integer `n`, return _the number of distinct solutions to the **n-queens puzzle**_.
**Example 1:**
**Input:** n = 4
**Output:** 2
**Explanation:** There are two distinct solutions ... | null | Backtracking | Hard | 51 |
1,043 | Hello everyone Welcome to my channel here I solve problems Lead code Today I will solve the daily Challenge This is task number 1043 divide the array to obtain the maximum amount level average we are given an array of integers R we need to divide it into consecutive subarrays of length no more than K after what divisio... | Partition Array for Maximum Sum | grid-illumination | Given an integer array `arr`, partition the array into (contiguous) subarrays of length **at most** `k`. After partitioning, each subarray has their values changed to become the maximum value of that subarray.
Return _the largest sum of the given array after partitioning. Test cases are generated so that the answer fi... | null | Array,Hash Table | Hard | 51 |
59 | hey so welcome back in this another daily code problem so today it's called spiral Matrix 2 and actually yesterday's problem was called spiral Matrix so it's kind of the what's the second version of it so very similar algorithm they just change it up a little bit so yeah let's get started so it's a medium level questio... | Spiral Matrix II | spiral-matrix-ii | Given a positive integer `n`, generate an `n x n` `matrix` filled with elements from `1` to `n2` in spiral order.
**Example 1:**
**Input:** n = 3
**Output:** \[\[1,2,3\],\[8,9,4\],\[7,6,5\]\]
**Example 2:**
**Input:** n = 1
**Output:** \[\[1\]\]
**Constraints:**
* `1 <= n <= 20` | null | Array,Matrix,Simulation | Medium | 54,921 |
173 | um hello so today we are going to do this problem uh part of lit code april daily challenge uh binary search three iterator um so the problem asks is um we get a binary search tree root node um and we want to um we want the iterator over the in-order traversal the iterator over the in-order traversal the iterator over ... | Binary Search Tree Iterator | binary-search-tree-iterator | Implement the `BSTIterator` class that represents an iterator over the **[in-order traversal](https://en.wikipedia.org/wiki/Tree_traversal#In-order_(LNR))** of a binary search tree (BST):
* `BSTIterator(TreeNode root)` Initializes an object of the `BSTIterator` class. The `root` of the BST is given as part of the co... | null | Stack,Tree,Design,Binary Search Tree,Binary Tree,Iterator | Medium | 94,251,281,284,285,1729 |
280 | what is up youtube today i'm going to be going over wiggle sore it's a medium problem on leak code if you guys haven't already check out my channel subscribe hit that like button and now let's get to the problem okay so we have wiggles or given an unsorted array nums reorder in place such that nums zero is less than or... | Wiggle Sort | wiggle-sort | Given an integer array `nums`, reorder it such that `nums[0] <= nums[1] >= nums[2] <= nums[3]...`.
You may assume the input array always has a valid answer.
**Example 1:**
**Input:** nums = \[3,5,2,1,6,4\]
**Output:** \[3,5,1,6,2,4\]
**Explanation:** \[1,6,2,5,3,4\] is also accepted.
**Example 2:**
**Input:** nums... | null | Array,Greedy,Sorting | Medium | 75,324,2085 |
1,696 | Loot Hello Guys Welcome To Your Dhund And Today We Will Discuss The Question Part Subscribe Withdraw Appointed subscribe and subscribe the Channel and subscribe the Related Question In The Last Decade Next Index And On Instagram Twitter The Video then subscribe to The Amazing Subscribe Particulars In Talking About This... | Jump Game VI | strange-printer-ii | You are given a **0-indexed** integer array `nums` and an integer `k`.
You are initially standing at index `0`. In one move, you can jump at most `k` steps forward without going outside the boundaries of the array. That is, you can jump from index `i` to any index in the range `[i + 1, min(n - 1, i + k)]` **inclusive*... | Try thinking in reverse. Given the grid, how can you tell if a colour was painted last? | Array,Graph,Topological Sort,Matrix | Hard | 664 |
991 | welcome to february's lego challenge today's problem is broken calculator on a broken calculator that has a number showing on its display we can perform two operations double multiply the number on the display by two decrement subtract one from the number on the display initially the calculator is displaying the number... | Broken Calculator | array-of-doubled-pairs | There is a broken calculator that has the integer `startValue` on its display initially. In one operation, you can:
* multiply the number on display by `2`, or
* subtract `1` from the number on display.
Given two integers `startValue` and `target`, return _the minimum number of operations needed to display_ `targ... | null | Array,Hash Table,Greedy,Sorting | Medium | 2117 |
790 | Hi gas welcome and welcome back to my channel so today our problem is domino and domino tiles so what have you given us in this problem statement here you have given us tiles of two types whose size is yours 2 * 1 and your shop is yours Domino is yours 2 * 1 and your shop is yours Domino is yours 2 * 1 and your shop is... | Domino and Tromino Tiling | global-and-local-inversions | You have two types of tiles: a `2 x 1` domino shape and a tromino shape. You may rotate these shapes.
Given an integer n, return _the number of ways to tile an_ `2 x n` _board_. Since the answer may be very large, return it **modulo** `109 + 7`.
In a tiling, every square must be covered by a tile. Two tilings are dif... | Where can the 0 be placed in an ideal permutation? What about the 1? | Array,Math | Medium | null |
824 | Yes dad don't remember I will be there with the prick for it though because once in you again the and a Beat when you to the fruit Is All we need to use and domestic tourists to you that s and in the Center of computer with several cases It will consist of markets and of working on which would like to converter tentacl... | Goat Latin | number-of-lines-to-write-string | You are given a string `sentence` that consist of words separated by spaces. Each word consists of lowercase and uppercase letters only.
We would like to convert the sentence to "Goat Latin " (a made-up language similar to Pig Latin.) The rules of Goat Latin are as follows:
* If a word begins with a vowel (`'a'`, `... | null | Array,String | Easy | null |
72 | in this video we'll be going over the memorization approach of edit distance in the previous video the recursive approach was very inefficient due to overlapping recursive calls and we are going to optimize it using memorization which means caching let's go over the thought process so the recursive approach is ineffici... | Edit Distance | edit-distance | Given two strings `word1` and `word2`, return _the minimum number of operations required to convert `word1` to `word2`_.
You have the following three operations permitted on a word:
* Insert a character
* Delete a character
* Replace a character
**Example 1:**
**Input:** word1 = "horse ", word2 = "ros "
**O... | null | String,Dynamic Programming | Hard | 161,583,712,1105,2311 |
856 | hello and welcome back again to lead coding on this channel we discuss problems which are frequently asked me programming interviews and try to approach them in a step-by-step manner approach them in a step-by-step manner approach them in a step-by-step manner we also discuss the space and the time complexity and sever... | Score of Parentheses | consecutive-numbers-sum | Given a balanced parentheses string `s`, return _the **score** of the string_.
The **score** of a balanced parentheses string is based on the following rule:
* `"() "` has score `1`.
* `AB` has score `A + B`, where `A` and `B` are balanced parentheses strings.
* `(A)` has score `2 * A`, where `A` is a balanced ... | null | Math,Enumeration | Hard | null |
818 | hey what's up guys chung here again and so today let's take a look at another lead cold hard problem here number 818 race car so you have a car and the car at position 0 and speed then you need the initial speed is 1 and at each step you can do two things either accelerate if you do accelerate your position the next po... | Race Car | similar-rgb-color | Your car starts at position `0` and speed `+1` on an infinite number line. Your car can go into negative positions. Your car drives automatically according to a sequence of instructions `'A'` (accelerate) and `'R'` (reverse):
* When you get an instruction `'A'`, your car does the following:
* `position += spee... | null | Math,String,Enumeration | Easy | null |
667 | Ajay Ko Hello Everyone Welcome to Code Scan Subir World Tarf Write Challenge and Problem subscribe and subscribe the Video then subscribe to Ka Selection Distance Problem Daily Sample Consider This Example in Easy Way Two Three Four Number This Side Subscribe Ka Main Tera Blood Pressure Number Stuart 3.2 Main Tera Bloo... | Beautiful Arrangement II | beautiful-arrangement-ii | Given two integers `n` and `k`, construct a list `answer` that contains `n` different positive integers ranging from `1` to `n` and obeys the following requirement:
* Suppose this list is `answer = [a1, a2, a3, ... , an]`, then the list `[|a1 - a2|, |a2 - a3|, |a3 - a4|, ... , |an-1 - an|]` has exactly `k` distinct ... | null | Array,Math | Medium | 526 |
1,277 | hello friends today lots of how to square sub-matrix with all one's given square sub-matrix with all one's given square sub-matrix with all one's given an M times and magics of ones and zeroes return how many square sub-matrix have return how many square sub-matrix have return how many square sub-matrix have all ones l... | Count Square Submatrices with All Ones | largest-multiple-of-three | Given a `m * n` matrix of ones and zeros, return how many **square** submatrices have all ones.
**Example 1:**
**Input:** matrix =
\[
\[0,1,1,1\],
\[1,1,1,1\],
\[0,1,1,1\]
\]
**Output:** 15
**Explanation:**
There are **10** squares of side 1.
There are **4** squares of side 2.
There is **1** square of side 3.... | A number is a multiple of three if and only if its sum of digits is a multiple of three. Use dynamic programming. To find the maximum number, try to maximize the number of digits of the number. Sort the digits in descending order to find the maximum number. | Array,Dynamic Programming,Greedy | Hard | null |
1,170 | hello everyone a leak of the day today our question is leaked out 1 7 l compares dreams by frequency of the smallest character this problem is favored by Google we can see Google has interviewed maybe like 17 times in the recent six pounds let's look at the question so first define a function f as over a string s and c... | Compare Strings by Frequency of the Smallest Character | shortest-common-supersequence | Let the function `f(s)` be the **frequency of the lexicographically smallest character** in a non-empty string `s`. For example, if `s = "dcce "` then `f(s) = 2` because the lexicographically smallest character is `'c'`, which has a frequency of 2.
You are given an array of strings `words` and another array of query s... | We can find the length of the longest common subsequence between str1[i:] and str2[j:] (for all (i, j)) by using dynamic programming. We can use this information to recover the longest common supersequence. | String,Dynamic Programming | Hard | 1250 |
667 | welcome to april's leeco challenge today's problem is beautiful arrangement 2. given two integers n and k you need to construct a list which contains n different positive integers ranging from 1 to n and obeys the following requirement suppose this list is a1a2 a3 all the way to a n then the list a1 minus a2 the absolu... | Beautiful Arrangement II | beautiful-arrangement-ii | Given two integers `n` and `k`, construct a list `answer` that contains `n` different positive integers ranging from `1` to `n` and obeys the following requirement:
* Suppose this list is `answer = [a1, a2, a3, ... , an]`, then the list `[|a1 - a2|, |a2 - a3|, |a3 - a4|, ... , |an-1 - an|]` has exactly `k` distinct ... | null | Array,Math | Medium | 526 |
57 | in this video we're going to take a look at a legal problem called insert interval so we're given a set of non-overlapping intervals non-overlapping intervals non-overlapping intervals and we want to insert a new interval into the intervals that we're given and if there's overlapping we want to make sure we merge the i... | Insert Interval | insert-interval | You are given an array of non-overlapping intervals `intervals` where `intervals[i] = [starti, endi]` represent the start and the end of the `ith` interval and `intervals` is sorted in ascending order by `starti`. You are also given an interval `newInterval = [start, end]` that represents the start and end of another i... | null | Array | Medium | 56,715 |
456 | hello and welcome to today's daily lead code challenge today we'll be solving question 456 called 132 pattern we'll be going through my thought process as I come up with solution and then stick around for the end of the video where I compare my solution to the solution of others that let's begin the question uh and so ... | 132 Pattern | 132-pattern | Given an array of `n` integers `nums`, a **132 pattern** is a subsequence of three integers `nums[i]`, `nums[j]` and `nums[k]` such that `i < j < k` and `nums[i] < nums[k] < nums[j]`.
Return `true` _if there is a **132 pattern** in_ `nums`_, otherwise, return_ `false`_._
**Example 1:**
**Input:** nums = \[1,2,3,4\]
... | null | Array,Binary Search,Stack,Monotonic Stack,Ordered Set | Medium | null |
212 | hi everyone I'm Dr Singh today we'll talk about the lead code problem word search second this is a good example to explain the use of try let us begin we are given a board consist cons in of an array of letters we are to search a given list of words in the board such that the letters in the word are adjacent that is ho... | Word Search II | word-search-ii | Given an `m x n` `board` of characters and a list of strings `words`, return _all words on the board_.
Each word must be constructed from letters of sequentially adjacent cells, where **adjacent cells** are horizontally or vertically neighboring. The same letter cell may not be used more than once in a word.
**Exampl... | You would need to optimize your backtracking to pass the larger test. Could you stop backtracking earlier? If the current candidate does not exist in all words' prefix, you could stop backtracking immediately. What kind of data structure could answer such query efficiently? Does a hash table work? Why or why not? How a... | Array,String,Backtracking,Trie,Matrix | Hard | 79,1022,1433 |
1,592 | that's all we code 1592 rearrange the spaces between words so the question goes like this so you are given us string a text and with a lot of spaces and that spaces could be anywhere before the sentence after the sentence in between the words and there could be any number of spaces like there an l could have three spac... | Rearrange Spaces Between Words | rearrange-spaces-between-words | You are given a string `text` of words that are placed among some number of spaces. Each word consists of one or more lowercase English letters and are separated by at least one space. It's guaranteed that `text` **contains at least one word**.
Rearrange the spaces so that there is an **equal** number of spaces betwee... | null | null | Easy | null |
226 | okay guys thank you for joining um today i want to solve with you lead code 226 which is inverting a binary tree if you're like me and you've never encountered binary trees before don't worry they seem scary but they're not that scary actually you just have to realize that they are data structures that you can manipula... | Invert Binary Tree | invert-binary-tree | Given the `root` of a binary tree, invert the tree, and return _its root_.
**Example 1:**
**Input:** root = \[4,2,7,1,3,6,9\]
**Output:** \[4,7,2,9,6,3,1\]
**Example 2:**
**Input:** root = \[2,1,3\]
**Output:** \[2,3,1\]
**Example 3:**
**Input:** root = \[\]
**Output:** \[\]
**Constraints:**
* The number of n... | null | Tree,Depth-First Search,Breadth-First Search,Binary Tree | Easy | null |
345 | guys uh today we're looking at uh the lead code 345 reverse spouse of a string write a function that takes the string as input and reverse only in the vowels of a string um input hello uh so vowels or aeiou um so e and o gets reversed and lead code uh we reverse the e right here and then we will reverse the e and o so ... | Reverse Vowels of a String | reverse-vowels-of-a-string | Given a string `s`, reverse only all the vowels in the string and return it.
The vowels are `'a'`, `'e'`, `'i'`, `'o'`, and `'u'`, and they can appear in both lower and upper cases, more than once.
**Example 1:**
**Input:** s = "hello"
**Output:** "holle"
**Example 2:**
**Input:** s = "leetcode"
**Output:** "leotc... | null | Two Pointers,String | Easy | 344,1089 |
759 | cool so we are given a list schedule of employees okay which represents the working time for each get each employee okay so it's like a schedule zero element will kind of contain the working time of zeroth employee each employee has a list of non-overlapping intervals has a list of non-overlapping intervals has a list ... | Employee Free Time | set-intersection-size-at-least-two | We are given a list `schedule` of employees, which represents the working time for each employee.
Each employee has a list of non-overlapping `Intervals`, and these intervals are in sorted order.
Return the list of finite intervals representing **common, positive-length free time** for _all_ employees, also in sorted... | null | Array,Greedy,Sorting | Hard | null |
332 | oh hey everybody this is Larry this is day 14th of July challenge do we have a new weekly problem now that's tomorrow okay hit the like button hit the Subscribe button join me on Discord let me know what you think about today's Forum uh I today I play pickle pickleball is it for the first time and I hurt myself uh this... | Reconstruct Itinerary | reconstruct-itinerary | You are given a list of airline `tickets` where `tickets[i] = [fromi, toi]` represent the departure and the arrival airports of one flight. Reconstruct the itinerary in order and return it.
All of the tickets belong to a man who departs from `"JFK "`, thus, the itinerary must begin with `"JFK "`. If there are multiple... | null | Depth-First Search,Graph,Eulerian Circuit | Hard | 2051,2201 |
106 | EPF and Compression Request Today We Are Going to Saab The Great Wealth and Valid Challenge and Today's Problem State Me Problems Caused by Negative from India and World Tamil Sunrise Subscribe * Input to Injured in Acid Subscribe * Input to Injured in Acid Subscribe * Input to Injured in Acid Info Someone with the Int... | Construct Binary Tree from Inorder and Postorder Traversal | construct-binary-tree-from-inorder-and-postorder-traversal | Given two integer arrays `inorder` and `postorder` where `inorder` is the inorder traversal of a binary tree and `postorder` is the postorder traversal of the same tree, construct and return _the binary tree_.
**Example 1:**
**Input:** inorder = \[9,3,15,20,7\], postorder = \[9,15,7,20,3\]
**Output:** \[3,9,20,null,n... | null | Array,Hash Table,Divide and Conquer,Tree,Binary Tree | Medium | 105 |
237 | hello guys welcome back to tech doors and in this video we will see how to delete node in a linked list so this is from lead code day 2 of the June challenge so let us now look at the problem statement the problem says that we are given a linked list and we are given just a single node in a linked list and we want to d... | Delete Node in a Linked List | delete-node-in-a-linked-list | There is a singly-linked list `head` and we want to delete a node `node` in it.
You are given the node to be deleted `node`. You will **not be given access** to the first node of `head`.
All the values of the linked list are **unique**, and it is guaranteed that the given node `node` is not the last node in the linke... | null | Linked List | Easy | 203 |
338 | hey everyone welcome back and today we'll be doing another lead code 338 counting bits this is an easy one given integer and written an array such that e for each i in a n s i is the number of ones in a binary expression so what they are trying to say is if we give you a number two you will compute the binary one at th... | Counting Bits | counting-bits | Given an integer `n`, return _an array_ `ans` _of length_ `n + 1` _such that for each_ `i` (`0 <= i <= n`)_,_ `ans[i]` _is the **number of**_ `1`_**'s** in the binary representation of_ `i`.
**Example 1:**
**Input:** n = 2
**Output:** \[0,1,1\]
**Explanation:**
0 --> 0
1 --> 1
2 --> 10
**Example 2:**
**Input:** n =... | You should make use of what you have produced already. Divide the numbers in ranges like [2-3], [4-7], [8-15] and so on. And try to generate new range from previous. Or does the odd/even status of the number help you in calculating the number of 1s? | Dynamic Programming,Bit Manipulation | Easy | 191 |
981 | hello everyone today we will solve a lead code problem 982 so in this problem we have to design a time-based key value data structure that time-based key value data structure that time-based key value data structure that can store multiple values for the same key at different time step and retrieve the key values at a ... | Time Based Key-Value Store | delete-columns-to-make-sorted | Design a time-based key-value data structure that can store multiple values for the same key at different time stamps and retrieve the key's value at a certain timestamp.
Implement the `TimeMap` class:
* `TimeMap()` Initializes the object of the data structure.
* `void set(String key, String value, int timestamp)... | null | Array,String | Easy | null |
460 | Hey everyone, I hope people will be well, friend, after a long time there has been a video, you know about it, I have always been following my rule of inconsistency, I do n't know when the size will be correct, there is a question, if it is okay, it is a very good question. And I am truthful, this problem comes in hard... | LFU Cache | lfu-cache | Design and implement a data structure for a [Least Frequently Used (LFU)](https://en.wikipedia.org/wiki/Least_frequently_used) cache.
Implement the `LFUCache` class:
* `LFUCache(int capacity)` Initializes the object with the `capacity` of the data structure.
* `int get(int key)` Gets the value of the `key` if the... | null | Hash Table,Linked List,Design,Doubly-Linked List | Hard | 146,588 |
1,329 | One We are We are We are going to clear the solution Soft Matrix Regularly Okay, so let's see this question, what is the best one, we will get 11 class tenth invitation matrix in food, M cross tank and eminent people cannot be okay, possibly different If possible, like this cream, it has some three, this is from one to... | Sort the Matrix Diagonally | minimum-cost-to-move-chips-to-the-same-position | A **matrix diagonal** is a diagonal line of cells starting from some cell in either the topmost row or leftmost column and going in the bottom-right direction until reaching the matrix's end. For example, the **matrix diagonal** starting from `mat[2][0]`, where `mat` is a `6 x 3` matrix, includes cells `mat[2][0]`, `ma... | The first move keeps the parity of the element as it is. The second move changes the parity of the element. Since the first move is free, if all the numbers have the same parity, the answer would be zero. Find the minimum cost to make all the numbers have the same parity. | Array,Math,Greedy | Easy | 1895 |
503 | we're going to take a look at a decoy problem called nest greater element number two so this question is very similar to the nest greater element number one question so i highly recommend to check out that question before this one so basically what we're trying to do is we're trying to find the nest greater element for... | Next Greater Element II | next-greater-element-ii | Given a circular integer array `nums` (i.e., the next element of `nums[nums.length - 1]` is `nums[0]`), return _the **next greater number** for every element in_ `nums`.
The **next greater number** of a number `x` is the first greater number to its traversing-order next in the array, which means you could search circu... | null | Array,Stack,Monotonic Stack | Medium | 496,556 |
1,372 | Hello everyone welcome, we are going to do video number 25 of my channel 1372 but it is a story based question, you will write a story and it will become a question, so it is actually easy, ok, so let's move ahead, the name of the question is Longest Zigzag text, is n't it binary, it is ok but more. It is not okay, you... | Longest ZigZag Path in a Binary Tree | check-if-it-is-a-good-array | You are given the `root` of a binary tree.
A ZigZag path for a binary tree is defined as follow:
* Choose **any** node in the binary tree and a direction (right or left).
* If the current direction is right, move to the right child of the current node; otherwise, move to the left child.
* Change the direction f... | Eq. ax+by=1 has solution x, y if gcd(a,b) = 1. Can you generalize the formula?. Check Bézout's lemma. | Array,Math,Number Theory | Hard | null |
1,022 | in this video I will solve with you challenge number 1022 some of route to leave binary numbers so in this challenge we are given a binary tree each node of these three has value of 0 or 1 and each pass from the root to one of the leads represents binary number and our task is to compute the sum of all binary numbers r... | Sum of Root To Leaf Binary Numbers | unique-paths-iii | You are given the `root` of a binary tree where each node has a value `0` or `1`. Each root-to-leaf path represents a binary number starting with the most significant bit.
* For example, if the path is `0 -> 1 -> 1 -> 0 -> 1`, then this could represent `01101` in binary, which is `13`.
For all leaves in the tree, c... | null | Array,Backtracking,Bit Manipulation,Matrix | Hard | 37,63,212 |
144 | hey there welcome back to lead coding in this video we are going to solve the question binary tree pre-order traversal question binary tree pre-order traversal question binary tree pre-order traversal so we have already covered the inorder traversal of a binary tree and in this video we will be covering the pre-order v... | Binary Tree Preorder Traversal | binary-tree-preorder-traversal | Given the `root` of a binary tree, return _the preorder traversal of its nodes' values_.
**Example 1:**
**Input:** root = \[1,null,2,3\]
**Output:** \[1,2,3\]
**Example 2:**
**Input:** root = \[\]
**Output:** \[\]
**Example 3:**
**Input:** root = \[1\]
**Output:** \[1\]
**Constraints:**
* The number of nodes ... | null | Stack,Tree,Depth-First Search,Binary Tree | Easy | 94,255,775 |
1,022 | Hello hello everybody welcome to my channel its all related problems mom root to leaf minor number se zor fruit lift representative number starting with most valued for example 5000 for lips in the tree white from delhi to the number subscribe Video from this Hair subscribe to that sister Hair to hair and hair to hair ... | Sum of Root To Leaf Binary Numbers | unique-paths-iii | You are given the `root` of a binary tree where each node has a value `0` or `1`. Each root-to-leaf path represents a binary number starting with the most significant bit.
* For example, if the path is `0 -> 1 -> 1 -> 0 -> 1`, then this could represent `01101` in binary, which is `13`.
For all leaves in the tree, c... | null | Array,Backtracking,Bit Manipulation,Matrix | Hard | 37,63,212 |
138 | Submitted to Live Today When Solving a Question of List Start the Name of the Question is Copy List on Random Contest Video Also Question and a Very Special for Electrification of Doom Swelling List Friend Thanks Giving Subsidies Note Contention National Anthem Point at Which Should Point To in Odisha Health is basical... | Copy List with Random Pointer | copy-list-with-random-pointer | A linked list of length `n` is given such that each node contains an additional random pointer, which could point to any node in the list, or `null`.
Construct a [**deep copy**](https://en.wikipedia.org/wiki/Object_copying#Deep_copy) of the list. The deep copy should consist of exactly `n` **brand new** nodes, where e... | Just iterate the linked list and create copies of the nodes on the go. Since a node can be referenced from multiple nodes due to the random pointers, make sure you are not making multiple copies of the same node. You may want to use extra space to keep old node ---> new node mapping to prevent creating multiples copies... | Hash Table,Linked List | Medium | 133,1624,1634 |
799 | hey everybody this is Larry this is me going to do day 24 of the September Lego daily challenge hit the like button hit the Subscribe button join me on Discord let me know what you think about today's Farm is 7.99 today's Farm is 7.99 today's Farm is 7.99 champagne Tower okay let's see so we stack classes in the permit... | Champagne Tower | minimum-distance-between-bst-nodes | We stack glasses in a pyramid, where the **first** row has `1` glass, the **second** row has `2` glasses, and so on until the 100th row. Each glass holds one cup of champagne.
Then, some champagne is poured into the first glass at the top. When the topmost glass is full, any excess liquid poured will fall equally to t... | null | Tree,Depth-First Search,Breadth-First Search,Binary Search Tree,Binary Tree | Easy | 94 |
938 | hey guys welcome back to another video and today we're going to be solving the leak code question range sum of a bst and a bsd is basically called a binary search tree and it's a tree based data structure which follows a certain set of rules and i'll be going over what those rules are real quickly so first let's see wh... | Range Sum of BST | numbers-at-most-n-given-digit-set | Given the `root` node of a binary search tree and two integers `low` and `high`, return _the sum of values of all nodes with a value in the **inclusive** range_ `[low, high]`.
**Example 1:**
**Input:** root = \[10,5,15,3,7,null,18\], low = 7, high = 15
**Output:** 32
**Explanation:** Nodes 7, 10, and 15 are in the ra... | null | Array,Math,Binary Search,Dynamic Programming | Hard | null |
990 | Hello everyone welcome to my channel with Mike so today we are going to do video number 21 of our playlist of graph concepts and questions okay and before starting watch some speeches and words of knowledge l b always waiting okay achhe jab lage ka Okay, when someone is engaged in good news linking, when the dog is oka... | Satisfiability of Equality Equations | verifying-an-alien-dictionary | You are given an array of strings `equations` that represent relationships between variables where each string `equations[i]` is of length `4` and takes one of two different forms: `"xi==yi "` or `"xi!=yi "`.Here, `xi` and `yi` are lowercase letters (not necessarily different) that represent one-letter variable names.
... | null | Array,Hash Table,String | Easy | null |
1,685 | so little 1685 sum of absolute differences in a sorted array so for this problem you're given an array of numbers of integers sorted and you need to return another array where every result of i is the sum of the absolute value of the difference between your current number and all of the other numbers okay right so let'... | Sum of Absolute Differences in a Sorted Array | stone-game-v | You are given an integer array `nums` sorted in **non-decreasing** order.
Build and return _an integer array_ `result` _with the same length as_ `nums` _such that_ `result[i]` _is equal to the **summation of absolute differences** between_ `nums[i]` _and all the other elements in the array._
In other words, `result[i... | We need to try all possible divisions for the current row to get the max score. As calculating all possible divisions will lead us to calculate some sub-problems more than once, we need to think of dynamic programming. | Array,Math,Dynamic Programming,Game Theory | Hard | 909,1240,1522,1617,1788,1808,2002,2156 |
1,023 | hello hi guys suggestion or bantu discus liquid problem number 102 3 and problem name is camel kiss matching software been given in the list strings basically in yield squares and patterns string ok be happy return list of indian values where happy return list of indian values where happy return list of indian valu... | Camelcase Matching | time-based-key-value-store | Given an array of strings `queries` and a string `pattern`, return a boolean array `answer` where `answer[i]` is `true` if `queries[i]` matches `pattern`, and `false` otherwise.
A query word `queries[i]` matches `pattern` if you can insert lowercase English letters pattern so that it equals the query. You may insert e... | null | Hash Table,String,Binary Search,Design | Medium | 2161 |
201 | hey guys welcome to a new video in today's video we're going to look at Elite code problem and the problem's name is bitwise and of numbers range so in this question we are given two integers left and right which represents the left bound and right bound of a range where both are inclusive so our task is to return the ... | Bitwise AND of Numbers Range | bitwise-and-of-numbers-range | Given two integers `left` and `right` that represent the range `[left, right]`, return _the bitwise AND of all numbers in this range, inclusive_.
**Example 1:**
**Input:** left = 5, right = 7
**Output:** 4
**Example 2:**
**Input:** left = 0, right = 0
**Output:** 0
**Example 3:**
**Input:** left = 1, right = 2147... | null | Bit Manipulation | Medium | null |
263 | hey yo what's up my little coders let me show you in this tutorial how to solve the lethal question 263 ugly number so write a program to check whether a given number is an ugly number and the ugly numbers are positive numbers whose prime factors only include two three or five so for those of you who don't know what is... | Ugly Number | ugly-number | An **ugly number** is a positive integer whose prime factors are limited to `2`, `3`, and `5`.
Given an integer `n`, return `true` _if_ `n` _is an **ugly number**_.
**Example 1:**
**Input:** n = 6
**Output:** true
**Explanation:** 6 = 2 \* 3
**Example 2:**
**Input:** n = 1
**Output:** true
**Explanation:** 1 has n... | null | Math | Easy | 202,204,264 |
77 | hey everyone today we are going to solve the readable question combinations so you are given integer n and Care return all possible combination of K numbers choosing from the range from 1 to n so you may return the answer in any order so let's see the example so you are given n equal 4 and k equal to and the output is ... | Combinations | combinations | Given two integers `n` and `k`, return _all possible combinations of_ `k` _numbers chosen from the range_ `[1, n]`.
You may return the answer in **any order**.
**Example 1:**
**Input:** n = 4, k = 2
**Output:** \[\[1,2\],\[1,3\],\[1,4\],\[2,3\],\[2,4\],\[3,4\]\]
**Explanation:** There are 4 choose 2 = 6 total combin... | null | Backtracking | Medium | 39,46 |
787 | in this video lecture we'll be solving this problem cheapest flights within case tops we've already solved this problem with two approaches in my previous two videos and I've attached the links to those videos in the description below so make sure to check them out so in this problem we are given end cities connected b... | Cheapest Flights Within K Stops | sliding-puzzle | There are `n` cities connected by some number of flights. You are given an array `flights` where `flights[i] = [fromi, toi, pricei]` indicates that there is a flight from city `fromi` to city `toi` with cost `pricei`.
You are also given three integers `src`, `dst`, and `k`, return _**the cheapest price** from_ `src` _... | Perform a breadth-first-search, where the nodes are the puzzle boards and edges are if two puzzle boards can be transformed into one another with one move. | Array,Breadth-First Search,Matrix | Hard | null |
86 | hello everyone welcome back here is when I'm saying today we are diving deep into lead code daily challenge number 86 partition list so our mission to partition a link at least around pivot value so sounds intriguing right so let's dive into a task so our task is simple given a link at least add value X we need to part... | Partition List | partition-list | Given the `head` of a linked list and a value `x`, partition it such that all nodes **less than** `x` come before nodes **greater than or equal** to `x`.
You should **preserve** the original relative order of the nodes in each of the two partitions.
**Example 1:**
**Input:** head = \[1,4,3,2,5,2\], x = 3
**Output:**... | null | Linked List,Two Pointers | Medium | 2265 |
483 | The question has been asked that we have to find out, so if anyone has given us a number, but the example [ given us a number, but the example [ given us a number, but the example is fine, then what is a good base, if there is any one number, then any one such country, any one such base also. If we represent this numbe... | Smallest Good Base | smallest-good-base | Given an integer `n` represented as a string, return _the smallest **good base** of_ `n`.
We call `k >= 2` a **good base** of `n`, if all digits of `n` base `k` are `1`'s.
**Example 1:**
**Input:** n = "13 "
**Output:** "3 "
**Explanation:** 13 base 3 is 111.
**Example 2:**
**Input:** n = "4681 "
**Output:** "... | null | Math,Binary Search | Hard | null |
418 | hey everyone welcome to my channel so in this video i'm going to try to solve this problem and at the same time i'm going to follow the general steps you should follow in the coding interview when i'm trying to solve this problem so first of all let's try to resort this problem to get a good understanding so during the... | Sentence Screen Fitting | sentence-screen-fitting | Given a `rows x cols` screen and a `sentence` represented as a list of strings, return _the number of times the given sentence can be fitted on the screen_.
The order of words in the sentence must remain unchanged, and a word cannot be split into two lines. A single space must separate two consecutive words in a line.... | null | String,Dynamic Programming,Simulation | Medium | 2082 |
201 | hello counters I'm Marita and today I have a very cool different we have another day of Fleet Code challenge and before I solve this problem again judging from problem title I think I can guess what the problem will be about I might be wrong so but before going to Cody I'm guessing the statement and I will first explai... | Bitwise AND of Numbers Range | bitwise-and-of-numbers-range | Given two integers `left` and `right` that represent the range `[left, right]`, return _the bitwise AND of all numbers in this range, inclusive_.
**Example 1:**
**Input:** left = 5, right = 7
**Output:** 4
**Example 2:**
**Input:** left = 0, right = 0
**Output:** 0
**Example 3:**
**Input:** left = 1, right = 2147... | null | Bit Manipulation | Medium | null |
1,872 | s tok uh problem number 8 1871 is it a patent vs. problem? Ah, in the same case of this problem, ah, now if you change the 4 types of 5 types, you will solve it by doing 5 things. Now, is there a surprise 4 meters? Like this, once or twice, with dp, first of all, from plan de dp. Schedule 1 person ah dp definition once... | Stone Game VIII | can-you-eat-your-favorite-candy-on-your-favorite-day | Alice and Bob take turns playing a game, with **Alice starting first**.
There are `n` stones arranged in a row. On each player's turn, while the number of stones is **more than one**, they will do the following:
1. Choose an integer `x > 1`, and **remove** the leftmost `x` stones from the row.
2. Add the **sum** of... | The query is true if and only if your favorite day is in between the earliest and latest possible days to eat your favorite candy. To get the earliest day, you need to eat dailyCap candies every day. To get the latest day, you need to eat 1 candy every day. The latest possible day is the total number of candies with a ... | Array,Prefix Sum | Medium | null |
16 | hello guys I hope you are all doing well in this video I'll show you how to solve the problem lead called three sum Clauses so let's get started so the problem is that they give us an array of integers and then enter your Target and they ask you to find the three integers in the array such that the sum is closest to th... | 3Sum Closest | 3sum-closest | Given an integer array `nums` of length `n` and an integer `target`, find three integers in `nums` such that the sum is closest to `target`.
Return _the sum of the three integers_.
You may assume that each input would have exactly one solution.
**Example 1:**
**Input:** nums = \[-1,2,1,-4\], target = 1
**Output:** ... | null | Array,Two Pointers,Sorting | Medium | 15,259 |
1,032 | this is uh one of the harder string search problems and here we are given a list of words beforehand and that list will not change but once we have stored that list of words and we will see how to store that once we have stored that list is fixed then we will have a bunch of queries coming to us and in each query we wi... | Stream of Characters | satisfiability-of-equality-equations | Design an algorithm that accepts a stream of characters and checks if a suffix of these characters is a string of a given array of strings `words`.
For example, if `words = [ "abc ", "xyz "]` and the stream added the four characters (one by one) `'a'`, `'x'`, `'y'`, and `'z'`, your algorithm should detect that the suf... | null | Array,String,Union Find,Graph | Medium | null |
1,727 | hello everyone i'm sean cannell so today um let's look at the new decode pro um problem one seven two seven largest sub matrix with rearrangement so we have a matrix of size and multiply n and we're allowed to re arrange as columns in any order for example we can swap column um the second column and the third column an... | Largest Submatrix With Rearrangements | cat-and-mouse-ii | You are given a binary matrix `matrix` of size `m x n`, and you are allowed to rearrange the **columns** of the `matrix` in any order.
Return _the area of the largest submatrix within_ `matrix` _where **every** element of the submatrix is_ `1` _after reordering the columns optimally._
**Example 1:**
**Input:** matri... | Try working backward: consider all trivial states you know to be winning or losing, and work backward to determine which other states can be labeled as winning or losing. | Math,Dynamic Programming,Breadth-First Search,Graph,Memoization,Game Theory | Hard | 805,949 |
102 | so the question is we are green with the tree and we need to print it by level so how I can print this tree as Elvan level Oda before moving on to this part let's first see how I went print this tree is like this to print that tree I'll use a Q Y Q because Q is a three-foot otters after because Q is a three-foot otters... | Binary Tree Level Order Traversal | binary-tree-level-order-traversal | Given the `root` of a binary tree, return _the level order traversal of its nodes' values_. (i.e., from left to right, level by level).
**Example 1:**
**Input:** root = \[3,9,20,null,null,15,7\]
**Output:** \[\[3\],\[9,20\],\[15,7\]\]
**Example 2:**
**Input:** root = \[1\]
**Output:** \[\[1\]\]
**Example 3:**
**I... | null | Tree,Breadth-First Search,Binary Tree | Medium | 103,107,111,314,637,764,1035 |
99 | hey guys how's everything going this is jason in this video i'm going to solve a problem from uh elite code it's been a long time since my last video about lead code okay i hope it helps let's begin okay this is number 99 from uh recover number 99 from uh recover number 99 from uh recover binary search tree bsc we're g... | Recover Binary Search Tree | recover-binary-search-tree | You are given the `root` of a binary search tree (BST), where the values of **exactly** two nodes of the tree were swapped by mistake. _Recover the tree without changing its structure_.
**Example 1:**
**Input:** root = \[1,3,null,null,2\]
**Output:** \[3,1,null,null,2\]
**Explanation:** 3 cannot be a left child of 1 ... | null | Tree,Depth-First Search,Binary Search Tree,Binary Tree | Medium | null |
1,710 | welcome to my channel so for this video we're going to analyze the daily challenge problem that is problem 1710 maximum units on a truck so for this problem here we are going to share a greedy method first i'll read through the statement of the problem and then look at one example and finally we share the short code so... | Maximum Units on a Truck | find-servers-that-handled-most-number-of-requests | You are assigned to put some amount of boxes onto **one truck**. You are given a 2D array `boxTypes`, where `boxTypes[i] = [numberOfBoxesi, numberOfUnitsPerBoxi]`:
* `numberOfBoxesi` is the number of boxes of type `i`.
* `numberOfUnitsPerBoxi` is the number of units in each box of the type `i`.
You are also given... | To speed up the next available server search, keep track of the available servers in a sorted structure such as an ordered set. To determine if a server is available, keep track of the end times for each task in a heap and add the server to the available set once the soonest task ending time is less than or equal to th... | Array,Greedy,Heap (Priority Queue),Ordered Set | Hard | null |
423 | Hello Hi Everyone Dad Sunny Kumar From IT BHU Welcome To My Channel Court With Sunny Today I Am Going To Discuss Your Problems Will Construct Original Digit Sperm English Index Number Four To Three And Problems Of Medium Type Of List Ko Difficult Subscribe Not Been Given In The String continued after english representa... | Reconstruct Original Digits from English | reconstruct-original-digits-from-english | Given a string `s` containing an out-of-order English representation of digits `0-9`, return _the digits in **ascending** order_.
**Example 1:**
**Input:** s = "owoztneoer"
**Output:** "012"
**Example 2:**
**Input:** s = "fviefuro"
**Output:** "45"
**Constraints:**
* `1 <= s.length <= 105`
* `s[i]` is one of ... | null | Hash Table,Math,String | Medium | null |
998 | hey everybody this is Larry this is January 20th um I'm doing lead code personal Larry challenge hit the like button hit the Subscribe button join me on Discord let me know what you think about this prom uh usually I do I pick a random one and I did actually pick this as an RNG but then I was like oh let's solve the pr... | Maximum Binary Tree II | check-completeness-of-a-binary-tree | A **maximum tree** is a tree where every node has a value greater than any other value in its subtree.
You are given the `root` of a maximum binary tree and an integer `val`.
Just as in the [previous problem](https://leetcode.com/problems/maximum-binary-tree/), the given tree was constructed from a list `a` (`root = ... | null | Tree,Breadth-First Search,Binary Tree | Medium | null |
290 | hey what's up guys Nick white here I do talk encoding stuff on Twitch in YouTube this problem is called word pattern also I do the premium Li code problems on my patreon and you could reach out to me at discord this is a word pad or an easy problem given a pattern and a string so we are given a pattern in a string STR ... | Word Pattern | word-pattern | Given a `pattern` and a string `s`, find if `s` follows the same pattern.
Here **follow** means a full match, such that there is a bijection between a letter in `pattern` and a **non-empty** word in `s`.
**Example 1:**
**Input:** pattern = "abba ", s = "dog cat cat dog "
**Output:** true
**Example 2:**
**Input:*... | null | Hash Table,String | Easy | 205,291 |
129 | hi everyone welcome back to the channel and Twitter business hourly for daily challenge problem number 129 some route to leave numbers so it's a interesting problem uh in which basically each path represents a number for example one two and one three is a path and this also represents a number so basically you have to ... | Sum Root to Leaf Numbers | sum-root-to-leaf-numbers | You are given the `root` of a binary tree containing digits from `0` to `9` only.
Each root-to-leaf path in the tree represents a number.
* For example, the root-to-leaf path `1 -> 2 -> 3` represents the number `123`.
Return _the total sum of all root-to-leaf numbers_. Test cases are generated so that the answer w... | null | Tree,Depth-First Search,Binary Tree | Medium | 112,124,1030 |
1,227 | the solution to this problem is going to have you saying you got to be kidding me this is one two seven airplane seat assignment probability um although this problem is classified as a medium and is found within the dynamic programming tagged list uh it's not a medium and I wouldn't really consider it a dynamic program... | Airplane Seat Assignment Probability | number-of-equivalent-domino-pairs | `n` passengers board an airplane with exactly `n` seats. The first passenger has lost the ticket and picks a seat randomly. But after that, the rest of the passengers will:
* Take their own seat if it is still available, and
* Pick other seats randomly when they find their seat occupied
Return _the probability th... | For each domino j, find the number of dominoes you've already seen (dominoes i with i < j) that are equivalent. You can keep track of what you've seen using a hashmap. | Array,Hash Table,Counting | Easy | null |
163 | hello everyone and welcome to my new video today we are gonna solve another lead code exercise in this Google interview questions course this exercise is called missing ranges and here they tell us that given asserted integral array nums where the range of elements are the inclusive Branch lower and upper return its mi... | Missing Ranges | missing-ranges | You are given an inclusive range `[lower, upper]` and a **sorted unique** integer array `nums`, where all elements are in the inclusive range.
A number `x` is considered **missing** if `x` is in the range `[lower, upper]` and `x` is not in `nums`.
Return _the **smallest sorted** list of ranges that **cover every miss... | null | Array | Easy | 228 |
1 | on everyone so today we're looking at lead code number one question called twosome and i believe this is the most popular question on leap code it's also i think the most frequently asked question as well let's take a look here yeah so you can see in the last six months it's just asked everywhere and a very common ques... | Two Sum | two-sum | Given an array of integers `nums` and an integer `target`, return _indices of the two numbers such that they add up to `target`_.
You may assume that each input would have **_exactly_ one solution**, and you may not use the _same_ element twice.
You can return the answer in any order.
**Example 1:**
**Input:** nums... | A really brute force way would be to search for all possible pairs of numbers but that would be too slow. Again, it's best to try out brute force solutions for just for completeness. It is from these brute force solutions that you can come up with optimizations. So, if we fix one of the numbers, say x, we have to scan ... | Array,Hash Table | Easy | 15,18,167,170,560,653,1083,1798,1830,2116,2133,2320 |
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