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Coding problems

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In this set67 problems31 easy29 medium7 hard

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Easy

31 problems

Two Sum
Easyalgorithms
Reverse String
Easyalgorithms
Fizz Buzz
Easyalgorithms
Valid Palindrome
Easyalgorithms
Contains Duplicate
Easyalgorithms
Valid Anagram
Easyalgorithms
Best Time to Buy and Sell Stock
Easyalgorithms
Binary Search
Easyalgorithms
Contains Duplicate
Easyarrays hashingarraysetduplicate-detection
Valid Anagram
Easyarrays hashingstringhash-mapfrequency-count
Majority Element
Easyarrays hashingarrayhash-mapfrequency-count
First Unique Character in a String
Easyarrays hashingstringhash-mapfrequency-count
Intersection of Two Arrays
Easyarrays hashingarraysetintersection
Single Number
Easyarrays hashingarraybit-manipulationxor
Word Frequency Count
Easyarrays hashingstringhash-mapfrequency-count
Count Set Bits
Easybit manipulationbit manipulationmathpopcount
Power of Two
Easybit manipulationbit manipulationmatheasy
Single Number
Easybit manipulationbit manipulationXOReasy
Count Odd Numbers in an Interval Range
Easymathmathcountingeasy
Hamming Distance
Easybit manipulationbit manipulationXOReasy
Valid Parentheses
Easystackstackstringeasy
Min Stack
Easystackstackdesigneasy
Implement Queue Using Two Stacks
Easyqueuequeuestackeasy
Reverse a Linked List (Array Representation)
Easylinked listlinked-liststackeasy
Merge Two Sorted Lists (Array Representation)
Easylinked listlinked-listtwo-pointerseasy
Next Greater Element I
Easystackstackmonotonic-stackhash-map
Reverse Words in a String
Easystringsstringstwo-pointerseasy
Valid Anagram
Easystringsstringshash-mapeasy
Longest Common Prefix
Easystringsstringseasyprefix
String Compression (RLE)
Easystringsstringseasyrun-length-encoding
Title Case a String
Easystringsstringseasyformatting

Medium

29 problems

Maximum Subarray
Mediumalgorithms
Maximum Sum Subarray of Length K
Mediumsliding windowsliding-windowarraysprefix-sum
Two Sum II - Input Array Is Sorted
Mediumtwo pointerstwo-pointersarraysbinary-search
Longest Substring Without Repeating Characters
Mediumsliding windowsliding-windowstringshash-map
Container With Most Water
Mediumtwo pointerstwo-pointersarraysgreedy
Fruit Into Baskets
Mediumsliding windowsliding-windowarrayshash-map
Minimum Window Substring
Mediumsliding windowsliding-windowstringshash-map
Trapping Rain Water
Mediumtwo pointerstwo-pointersarraysdynamic-programming
Number of Subarrays with Product Less Than K
Mediumsliding windowsliding-windowarraystwo-pointers
Coin Change: Minimum Coins
Mediumdynamic programmingdynamic-programmingbottom-upunbounded-knapsack
Longest Palindromic Subsequence
Mediumdynamic programmingdynamic-programminginterval-dpstrings
Unique Paths with Obstacles
Mediumdynamic programmingdynamic-programminggrid2d-dp
Jump Game II: Minimum Jumps
Mediumdynamic programmingdynamic-programminggreedyarrays
Partition Equal Subset Sum
Mediumdynamic programmingdynamic-programming0-1-knapsacksubset-sum
Word Break
Mediumdynamic programmingdynamic-programmingstringshash-set
Maximum Product Subarray
Mediumdynamic programmingdynamic-programmingarrayskadane-variant
Reverse Integer
Mediummathmathmediumoverflow
Factorial Trailing Zeroes
Mediummathmathcountingmedium
Daily Temperatures
Mediumstackstackmonotonic-stackmedium
Parse a CSV Line
Mediumparsingstringsmediumparsing
Longest Substring Without Repeating Characters
Mediumstringsstringsmediumsliding-window
Count and Say
Mediumstringsstringsmediumrun-length-encoding
Binary Tree Right Side View
MediumBFS / Treesbfstreelevel-order
Number of Islands
MediumDFS / Graphsdfsbfsgraph
Course Schedule
MediumGraphs / Topological Sorttopological-sortdfscycle-detection
Lowest Common Ancestor of a BST
MediumTrees / BSTbstlcatree-traversal
Rotting Oranges
MediumBFS / Gridsbfsgridmulti-source-bfs
Max Area of Island
MediumDFS / Graphsdfsgridconnected-components
Clone Graph
MediumGraphs / BFSgraphadjacency-listbfs

Hard

7 problems

Merge K Sorted Arrays
Hardheapsheappriority-queuemerge
Minimum Interval to Include Each Query
Hardintervalsintervalsheapsorting
Ship Packages Within D Days
Hardbinary search on answerbinary-searchgreedybinary-search-on-answer
Median of Two Sorted Arrays
Hardbinary searchbinary-searchdivide-and-conquerarray
Maximum Non-Overlapping Intervals Count
Hardintervalsintervalsgreedysorting
Word Search II
Hardbacktrackingbacktrackingtriedfs
Kth Smallest Element in a Sorted Matrix
Hardheapsheappriority-queuebinary-search