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