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