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