154 Problems
215 Problems
105 Problems
Reverse an Integer
Find the Max Element in a Binary Tree Recursively
Delete a List's Tail Node
Find the N^{th} Node from the end without using extra memory - Linked List
Image Manipulation
Even or Odd?
Iterative BST Validation
Implement the Breadth First Search Algorithm for a Graph
Graph Depth First Search
Convert a Binary Tree to its Mirror Image
Minimum Sum Path in a Triangle
Find the k^{th} Smallest Node in a BST
Recursive Preorder Traversal
Find the Lowest Common Ancestor of Two Tree Nodes
Maximum Sum Path
Find the Middle of a List in a Single Pass
Find the Diameter of a BST
Number of Full Nodes in a Binary Tree
Rotate a Square Image Counterclockwise
Merge Two Sorted Arrays
Recovering IPv4 Addresses
String Compression
Remove the "N^{th} from the end" Node from a Singly-Linked List
Find the k^{th} Largest Node in a BST
Subset Summation with Number Constraint
Find the Maximum Contiguous Subsequence in an Array
Delete the Node at the Specific Position in a Doubly Linked List
Generate Combinations of Parentheses
Reverse a Linked List in Pairs
Insert a Node at the Front of a Linked List
Does an Element N Exist in a Given Binary Tree?
BST Validation
Natural Language Parser
Print all Possible Characters
Even Split
Selection Sort
Mirror Mirror on the Wall ...
Insert a Node at the Tail of a Doubly Linked List
Insert a Node at the Head of a Circular Linked List
Unique Chars in a String
Delete the Node at the Head of a Doubly Linked List
Delete the Tail Node of a Doubly Linked List
Recursive Inorder Traversal
Recursive Postorder Traversal
Iterative Postorder Traversal
Delete a List's Head Node
Roll the Dice!
Insert Stars
Parse Simple Mathematical Expressions
Print Paths
Boggle with Electronic Dictionary
Binary Search on Array of Integers
Couple Sum
Add Two Linked List-ish Numbers
Height of a Binary Tree
Find a BST Node
Find the Missing Number in a Set of Numbers from 1 to 10
Flip it!
Longest Non-Repeating Substring
Looping Lists : Space complexity O(n)
Boggle Search
Bubble Sort
1-800-PROBLEM
Longest Palindromic Substring
Is this List a Palindrome?
Permutations!
Find the Sum of all Elements in a Binary Tree Iteratively
Find the N^{th} Node from the End - Linked List
Flip bits in a matrix
Stock Market Oracle
Find the Number that Appears Once
POW!
Reverse a Singly Linked List
Combinations and Permutations
Delete a Circular-Linked List's Tail Node
Palindrome Tester
Array Partition
Full Tree Decompression
Insert a Node at the Specified Position in Doubly Linked List
Maximum Coordinates!
Pascal's Triangle
Are these Binary Trees Identical?
Check a Linked List for Loops or Cycles With O(1) Space Complexity
Count Paths on a Game Board
Minimum Depth of a Tree
Is this Integer a Palindrome?
Minimum Sum Path
Snake
Fill in the Ancestors of the Node in a Binary Tree
Implement the Depth First Search traversal Algorithm in a Grap
Iterative Preorder Traversal
Number of Half Nodes in a Binary Tree
Implement Breadth First Search Traversal Algorithm in a Grap
Reverse Words with Punctuation
Implement a Least Recently Used (LRU) Cache
Binary Tree Subsets with Same Sum
Balanced Braces
Count 1
s in a Binary Representation
Knapsack Algorithm
Merge Two Sorted Integer Arrays in Linear Time
Addition of Binary Strings
Iterator of Binary Search Tree with Nodes Containing Integer Data
Day with Maximum Difference in Temperatures
Soccer Team with Minimum Difference in Goals
Path between Two Input Words in a Dictionary
A million lines of code!
Tail N Number of Lines from an Input File
Add Two Numbers without using Plus Sign
Integer to Roman
Longest Consecutive Integers Set in an Array
Multiplication of Arrays
First N Prime Numbers
Rotate an Array to the Right.
Duplicate neighbours
Tail word length
Dominant Element
Merge Integer Ranges
Insert and Merge Ranges
Look and Say Sequence
Triple Sum
Quadruple Sum
Find Needle in a Haystack
Minimum Sub Array Size for a Target
Make Palindrome
Sum Root-to-Leaf Numbers
Range of a Number in an Array
Rightmost Nodes of a Tree
Fraction to Decimal
Excel - Column Name to Number
Excel - Column Number to Column Name
Chocolate time!
Unique Routes!
Break a Word!
Sorted Linked List into BST
Evaluate Postfix Notation
Decode Numbers!
Circular route
Minimum Window Sequence
Validate a Sudoku
Robbery
Division
Longest Common Prefix in a group of Strings
Wildcard Pattern Matching
Binary Gap
Repeated Sequences(DNA)
Merge array into the Largest Number
Horizontal Flip
Minimum number of Jumps
Longest substring with two Unique Characters
Simplify file Path
Sorted Array into BST
Compare Two Versions
Re-arrange Linked List in Pairs
Levelorder Traversal
Find the Maximum BST Node
Count the Leaves!
N-Ary Tree Serialization
HashMap with Random Value Picker
Happy Numbers!
Find the First Non Duplicate Character in a String
Print a Binary Tree Level by Level
Mobile Game Range Module - Inserting Ranges
Find the Minimum BST Node
Making Change
Insert a Node at a specified position in a Linked List
Repeated Elements in an Array
Matrix Max Sum Path with DFS
Reverse Level Order Traversal
Insert a Node at the Tail of a Circular Linked List
Replace all Spaces
Largest Square
Distance between two nodes in a Binary Tree
Steal the Node
Print all Nodes in the Range a .. b in a given BST
Distance of a node from the root
Jam into a BST
Implement the Djikstra Shortest Path Algorithm in a Graph
Binary Tree Serialization
Find the size of the Binary Tree
Delete the Head Node of a Circular Linked List
Fibonacci Number
Iteratively, find the Max Element in a Give Binary Tree
Find the Maximum Number of Repetitions
Find a Node in a Binary Tree Without Using Recursion
Find the Transpose of a Square Matrix
Recursive String Permutation
Check Balanced Parentheses
Introduction to Tries
Insert a Node at the Head in a Doubly Linked List
Power of 2
Binary Representation
Remove Duplicates from a List of Words
Matrix Max Sum Path with Dynamic Programming
Bit Conversion
Isomorphic Strings
Max Gain
Remove Duplicate Nodes
Rotate Linear Array
Rotate a Square Image Clockwise
Anagrams
Subset Summation
Iterative Inorder Traversal
Find the Level that has the Maximum Sum
Find the Sum of all Elements in a Binary Tree
Insert a Node at the End of a Linked List
Better Fibonacci
Bit Swapping
Mobile Game Range Module - Merging Ranges
Reverse a string
Recursively Merge Two Sorted Linked Lists
Delete the Node at a Particular Position in a Linked List
The Deepest Node
Word Similarity - Edit Distance
Boggle with Paper Dictionary
Merge k Sorted Linked Lists
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Java
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