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