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