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Data Structures and Algorithm Programs
- Language: Java
- Data Structures & imp classes
- Basic Programs
- Algorithms
- Top Companies (FAANG / MAANG) hiring process
- Companies frequency questions
- Sources
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- Dynamic int[] Array
- Stream API
- Collections Utility Class
- List
- LinkedList, DoubleLinkedList & CircularLinkedList
- HashMap
- Queue, Dequeue & PriorityQueue
- Stack
- IteratorExample — Iterator, ListIterator, Spliterator, Enumeration & ConcurrentModificationException CME
- Binary Search
- BinaryTreeNode sample / example class
- BinaryTree Basics
- Binary Search Tree BST
- Graphs
- Disjoint Set Union DSU / Union Find
- Annotation Type
- Enum Types & Conversions
- Functional Interface
- Record
- Date & Time
- Multi-Threading in Java
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- Median of Two Sorted Arrays
- Search in Rotated Sorted Array
- Find First and Last Position of Element in Sorted Array
- Search Insert Position
- Search in 2D Sorted Matrix
- BinaryTree MaximumPathSum
- Find Min in RotatedSortedArray
- Guess Number Higher or Lower
- Successful Pairs of Spells and Potions
- Find Peak Element
- Koko Eating Bananas
- H-Index
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- InvertBinaryTree
- BinaryTreeInOrderTraversal
- ValidateBinarySearchTree
- SymmetricTree
- BinaryTree LevelOrderTraversal
- BinaryTree using PreOrder & InOrder Traversals
- SortedArray to BinarySearchTree
- Flatten BinaryTree to LinkedList
- BinaryTree RightSideView
- Kth Smallest Element in BST
- Lowest Common Ancestor of a Binary Tree / LCA of BT
- Lowest Common Ancestor of a Binary Search Tree / LCA of BST
- PathSumIII
- Diameter of BinaryTree
- Leaf Similar Trees
- Count Good Nodes in Binary Tree
- Longest ZigZag Path in a Binary Tree
- Maximum Level Sum of a Binary Tree
- Search in a Binary Search Tree
- Delete Node in a BST
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- Number of Connected Components in an Undirected Graph
- Number Of Provinces
- Number of Islands
- Find the Index of the First Occurrence in a String
- Redundant Connection
- Accounts Merge
- Number of Operations to Make Network Connected
- Regions Cut By Slashes
- Satisfiability of Equality Equations
- Min Cost to Connect All Points
- Number Of Good Paths
- Longest Consecutive Sequence
- Path With Minimum Effort
- Minimize Hamming Distance After Swap Operations
- Evaluate Division
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- Fibonacci_DP_Recursive_Backtracking & DP intro
- Fibonacci_DP_TopDown_Memoization & DP intro
- Fibonacci_DP_BottomUp_Tabulation & DP intro
- Fibonacci_DP_BottomUp_NoMemory & DP intro
- Knapsack_01_DP_SubsetSumProblem & Knapsack 0-1 Intro 🔥
- Knapsack_Bounded_DP_BoundedSubsetSumProblem & Knapsack Bounded Intro
- Knapsack_Unbounded_DP_CoinChange & Knapsack Unbounded Intro
- Knapsack_Fractional_DP_FractionalKnapsackProblem(Weights[], Values[], Capacity) & Fractional Knapsack Problem Intro
- Knapsack_01_DP Partition Equal Subset Sum
- Knapsack_Unbounded_DP Minimum Number of Primes to Sum to Target
- LongestCommonSubsequence
- LongestPalindromicSubstring
- LongestValidParenthesis
- UniquePaths
- MinimumPathSum
- ClimbingStairs
- Edit Distance - Levenshtein Distance Algorithm
- PascalsTriangle
- WordBreak
- MaximumProductSubArray
- HouseRobber
- LongestIncreasingSubsequence
- PerfectSquares
- Maximum possible stability of any subset of servers
- N-th Tribonacci Number
- Min Cost Climbing Stairs
- Domino and Tromino Tiling
- Best Time to Buy and Sell Stock
- Best Time to Buy and Sell Stock II
- Best Time to Buy and Sell Stock with Transaction Fee
- JumpGame I
- JumpGame II
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- OptimizingBoxWeights
- MinimumNumberOfSwapsToSort
- JumpGame I
- JumpGame II
- Best Time To Buy And Sell Stock
- Partition Labels
- H-Index
- Gas Station
- Candy
- Maximum SubArray - Kadane's Algorithm & DC
- Maximum Frequency After Subarray Operation
- Maximize Y‑Sum by Picking a Triplet of Distinct X‑Values
- Reorganize String
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- Group Anagrams
- RansomNote
- Longest Consecutive Sequence
- Two Sum
- SubArraySumEqualsK (contiguous sub-array sum)
- Find the Difference of Two Arrays
- Unique Number of Occurrences
- Determine if Two Strings Are Close
- Equal Row and Column Pairs
- LRU Cache
- Maximize Y‑Sum by Picking a Triplet of Distinct X‑Values
- Analyze User Website Visit Pattern
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- MaximumRepeatingNumber
- Closest Equal Element Queries
- Maximum Unique SubArray Sum After Deletion
- Count Beautiful Numbers
- Minimum Cost to Reach Every Position
- Kids With the Greatest Number of Candies
- Can Place Flowers
- Minimum Pair Removal to Sort Array I
- Increasing Triplet Subsequence
- Count Special Quadruplets
- Count Good Triplets
- Merge Sorted Array
- Remove Element
- Remove duplicates from Sorted Array
- Remove duplicates from Sorted Array II
- Rotate Array by K times
- H-Index
- Insert Delete GetRandom O(1)
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- MiddleOfTheLinkedList
- Reverse LinkedList
- Zipper LinkedLists
- Add Two Numbers
- Remove Nth Node From End of List
- Merge Two Sorted Lists
- Merge k Sorted Lists
- Swap Nodes In Pairs
- Reverse Nodes in k-Group
- Copy List with Random Pointer
- LinkedListCycle
- LinkedListCycle 2
- SortList
- LRUCache
- Intersection of Two LinkedLists
- Palindrome LinkedList
- Delete the Middle Node of a Linked List
- Odd Even Linked List
- Maximum Twin Sum of a Linked List
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- Maximum Average SubArray I & Fixed Sliding Window Intro
- Longest Substring Without Repeating Characters & Dynamic Sliding Window Intro
- Find all the Anagrams in a String
- Minimum Window Substring
- Sliding Window Maximum
- Maximum Number of Vowels in a Substring of Given Length
- Max Consecutive Ones III
- Longest SubArray of 1's After Deleting One Element
- Minimum Size Subarray Sum
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- Parentheses perfection kit
- Binary String to Palindrome
- Longest Common Prefix
- Longest Palindrome After Substring Concatenation I
- Merge Strings Alternately
- Greatest Common Divisor of Strings
- Reverse Vowels of a String
- Reverse Words in a String
- String Compression
- Zigzag Conversion
- Roman to Integer
- Integer to Roman
- Length of Last Word
- Text Justification
- Longest Common Prefix Between Adjacent Strings After Removals
- Process String with Special Operations I
- Hiring Process
- Check out my "Amazon Interview Process" personal Google Keep notes
- LeetCode Amazon top questions
- GitHub - xizhang20181005/Leetcode_company_frequency #amazon
- GiftingGroups
- OptimizingBoxWeights
- MinimumNumberOfSwapsToSort
- Parentheses perfection kit
- Maximum possible stability of any subset of servers
- Binary String to Palindrome
- Find median for k elements in n array. Return new int[]{maxMedian, minMedian}
- 1 to m-1 cities and n warehouses, cityStart=[1,2,1], cityEnd=[2,5,9]. cityStart.length == cityEnd.length == n of warehouses. Multiple warehouse connect to same city. Find cityWarehouseCounter <city, num of warehouses>
- Best Time to Buy and Sell Stock
- LRU Cache
- LongestPalindromicSubstring
- Maximum SubArray - Kadane's Algorithm & DC
- Maximum Frequency After Subarray Operation
- Number of Islands
- Maximize Y‑Sum by Picking a Triplet of Distinct X‑Values
- Find First and Last Position of Element in Sorted Array
- Reorganize String
- Analyze User Website Visit Pattern
- Group Anagrams
- Word Search
- Add Two Numbers
- Meeting Rooms II
- Knapsack_Unbounded_DP Minimum Number of Primes to Sum to Target
- SubArraySumEqualsK (contiguous sub-array sum)
- Longest Substring Without Repeating Characters
- Trapping Rain Water
- Process String with Special Operations I
- Minimum Window Substring
- Longest Common Prefix
- Container With MostWater - maxArea
- JumpGame I
- JumpGame II
- Valid Parentheses
- Generate Parentheses
- Copy List with Random Pointer
- Two Sum
- Two Sum II - Input Array Is Sorted
- 3Sum
- Merge Intervals
- Sudoku Solver
- Edit Distance - Levenshtein Distance Algorithm
- Product of Array Except Self
- WordBreak
- Course Schedule - Khan's Algorithm using Topological Sort
- Course Schedule II
- Lowest Common Ancestor of a Binary Tree / LCA of BT
- Asteroid Collision
- Reverse Integer
- Hiring Process
- LeetCode Google top questions
- GitHub - xizhang20181005/Leetcode_company_frequency #Google
- Hiring Process
- LeetCode Microsoft top questions
- GitHub - xizhang20181005/Leetcode_company_frequency #Microsoft
- Hiring Process
- LeetCode Meta / Facebook top questions
- GitHub - xizhang20181005/Leetcode_company_frequency #Facebook
- My "50 Days badge 2025" received on 12 March 2025
- My "Top 100 Liked" badge received on 20 March 2025
- My "100 Days badge 2025" received on 01 May 2025
- My "LeetCode 75" badge received on 26 May 2025
- My AMAZON OA Question 1 Discussion Parentheses Perfection Kit
- My AMAZON OA Question 2 Discussion Get Maximum Stability
- From my LeetCode experience- leetcode/srinivasvadige
- Hackerrank
- Personal experience and research
- Official java documentations, blogs
- WilliamFiset - YT Data structures playlist
- takeuforward.org - Strivers A2Z DSA Course/Sheet
- COURSERA DSA ROADMAP PART 1
- COURSERA DSA ROADMAP PART 2
- GFG DSA course
- FCC DSA course with 48hrs YT video
- GFG interview DSA FAQs
- Columbia University DSA Research Papers
Author: Srinivas Vadige
Email: srinivas.vadige@gmail.com
LinkedIn: linkedin.com/in/srinivasvadige
My Leetcode profile: leetcode.com/srinivasvadige
This repository is released under the MIT license. In short, this means you are free to use this software in any personal, open-source or commercial projects. Attribution is optional but appreciated.
Other Github project (williamfiset/Algorithms and MaRuifeng/DummyLovesAlgorithms)
- Integer Array
- Find the largest sub-array sum of a given integer array
- Find the largest absolute difference of two non-overlapping sub-arrays of a given integer array
- Find total number of reverse pairs in a given integer array
- Find the largest sum of a sub-array with size K in a given integer array
- Find the k'th smallest item from a given array of distinct integers
- Find number pairs each of which sums up to a fixed value from an integer array
- All hail Recursion! Find required add and subtract operations to produce a fixed sum
- Find the greatest common divisor of an array of integers
- Print numbers along matrix diagonals
- Print spiral numbers
- Bitwise operations
- Merge sorted integer arrays
- All hail Recursion! Find all subsets of an integer set
- Patch a given array to produce list of sums from 1 to N
- Binary search in a sorted array rotated at an unknown pivot
- All hail Recursion! Number permutation
- All hail Recursion! Number combination
- Random number with different entropies
- Binary search in matrix
- Multiple-Condition Check Insert intervals
- Reverse an integer number
- Recover a rotated sorted array
- NP Hard Bin packing problem
- Boyer–Moore Majority Vote Algorithm Find majority numbers
- Monkey crossing river
- Number of ways to sum up to a given number with consecutive positive integers
- Array based circular queue
- Linked List
- Dynamic Programming
- Fibonacci Numbers
- Binomial Coefficients
- Catalan Numbers Find all expressions of balanced n pairs of parentheses
- Coin change problems
- Number of possible combinations for given sum
- List of possible combinations for given sum
- Least number of coins needed for given sum
- Number arrangements to get a fixed sum
- Maximum sub-array sum
- Ugly Numbers
- Maximum stock profit
- Digit sequence decoder
- Longest common subsequence
- Longest common substring
- Longest increasing subsequence
- Edit distance algorithm
- Set partition for minimum sum difference
- Distance and steps
- Longest path in matrix
- NP-Complete Subset of fixed sum
- Optimal coin game strategy
- Minimum insertions for palindrome
- NP-Complete 0-1 Knapsack problem
- Wildcard pattern match check
- Beware of integer overflow! Boolean parenthesization
- DP Enhancement Find required add and subtract operations to produce a fixed sum
- Shortest common supersequence
- Least arithmetic operations for matrix chain multiplication
equalsandhashCodemethod override Rod cutting for maximum gain- Resolve a string with dictionary words
- Rope cutting for maximum length product
- Dice rolling for fixed sum
- Egg dropping puzzle
- K non-overlapping subarrays of maximum sum
- LEGO part assembler
- NP-Complete Minimum time for fixed sum of points
- String
- Remove duplicates in string
- Remove alternate duplicates in string
- Remove adjacent duplicates in string
- Remove consecutive duplicates in string
- Longest valid parentheses substring
- Parentheses checker
- In-place string rotator
- Backtracking String permutation
- KMP Algorithm Search for patterns in string
- DP Check interleaved string
- Minimum window substring
- IPv4 address regex matcher
- Functional Programming Credit card number Luhn check
- String to int converter
- Longest palindromic substring
- Binary Tree
- Plain Binary Tree implementation with linked nodes
- Pre-order Traversal
- Post-order Traversal
- Level-order Traversal
- Clone via pre-order traversal
- Serialization/de-serialization
- Plain Binary Search Tree implementation with linked nodes
- Parse a BST from its pre-order traversal
- Parse a BST from its post-order traversal
- Parse a BST from its level-order traversal
- Convert a BT to a BST with tree structure maintained
- Divide and Conquer Search range in BST
- Sum up greater keys with each node in BST
- Sum up greater keys for each node in BST
- Convert integer array to BST
- Convert integer linked list to BST
- All possible BSTs from 1 to N Catalan Numbers
- Convert BST to min heap
- Convert BT to doubly linked list
- Convert complete BST to conditional min heap where left sub-tree smaller than right sub-tree
- Binary tree mirror image
- Plain Binary Tree implementation with linked nodes
- Binary Heap
- Graph
- Plain Directed Graph implementation with adjacency list
- Breadth First Search
- Depth First Search
- Linear paths from source to destination
- Plain Directed Graph implementation with adjacency list
- Backtracking Technique