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