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