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