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