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