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