Arrays

• Arrange Coins
• Build Array from Permutations
• Circular Array Loop
• Container with Most Water
• Find minimum in rotated sorted array
• Fruits into Baskets II
• Intersection of Two Arrays
• Jump Game II
• Jump Game
• Matrix Diagonal Sum
• Maximum Number of Fruits Collected
• Median of two sorted arrays
• Permutations
• Remove All Repeat Numbers from Sorted Array
• Remove Duplicates from Sorted Array
• Remove Element
• Rotate Array
• Range Sum Query
• Range Sum Query (2D)
• Search a 2d Matrix
• Search Insert Position
• Search in Rotated Array
• Squares of a Sorted Array
• Sort an Array
• Summary Ranges
• Two Sums
• Maximum Subarray
• Minimum Size Subarray Sum
• 3Sum

Backtracking

• Shortest Path in Binary Matrix
• Generate Binary Strings without Adjacent Zeros

Bitwise Operators

• Single Number in an Array
• Single Element in a sorted array

Caches

• Least Recently Used Cache

Dynamic Programming

• Climbing Stairs
• Soup Servings

Graphs

• Course Schedule II
• Course Schedule IV
• Cheapest Flights within K Stops
• Clone Graph
• Find Center of Star Graph
• Find the City With the Smallest Number of Neighbors at a Threshold Distance
• Letter combinations of a phone number
• Number of Islands
• Network Delay Time
• Reconstruct Itinerary
• Same Tree
• Word Ladder

Hashmaps (Hashes)

• Insert Delete GetRandom O(1)
• K Weakest Rows in a Matrix
• Majority Element
• Ransom Note
• Word Pattern

Heaps

• Find K Closest Elements
• Find K Pairs with smallest sums
• Merge k Sorted Lists
• Kth Largest Element in a Stream
• Last Stone Weight
• Relative Ranks 0 Sort Characters by Frequency

Linked Lists

• Add Two Numbers
• All O'one Data Structure
• Convert Sorted List to Binary Search Tree
• Delete Middle of a Linked List
• Linked List Cycle
• Linked List Cycle II
• Merge Two Sorted Lists
• Middle of the Linked List
• Remove duplicates from sorted list
• Remove Duplicates from Sorted Array II
• Remove nth Node from end of list
• Reverse Linked Lists
• Rotate Linked List
• Sort List

Math

• Fibonacci Number
• Integer to Roman
• Largest Number
• Largest Perimeter Triangle
• Plus One
• Power of Four
• Powers of Three
• Product of Array Except Self
• Range Product Queries of Powers
• Reordered Power of Two
• Roman to Integer
• Ways to Express an Integer as Sum of Powers

Searches

• Single Element in a sorted array
• Find First and Last Position Element in Sorted Array
• Koko Eating Bananas
• Kth Smallest Element in a Sorted Matrix
• Square Root of X

Sorts

• Sort An Array
• Insertion Sort List
• Insert Interval
• Sort Colors
• Relative Sort Array
• Kth Largest element in array
• Top K frequent elements
• Contains Duplicates II
• Sliding Window Maximum
• Merge Intervals
• Non Overlapping Intervals

Stacks

• Largest Rectangle in Histogram
• Circular Deque
• MinStack
• Next Greater Element
• Stack with Incremental Operation
• Valid Parenthesis
• Queue Using Stacks

Strings

• Add and Search Words Data Structure
• Find the Index of the First Occurence in a String
• Implement Trie /try/ or prefix tree
• Is Subsequence
• Length of Last Word
• Longest Substring without Repeating Characters
• Longest Common Prefix
• Longest Duplicate Substring
• Longest Palindrome Substring
• Map Sum Pairs
• Maximum 69 Number
• Minimum Window Substring
• Palindrome Number
• Prefix and Suffix Search
• Reverse Integer
• Remove K Digits
• Reverse Words in a String
• Shortest Palindrome
• Valid Palindrome

Trees

• Balanced Binary Tree
• Binary Tree Right Side View
• Binary Tree Preorder Traversal
• Construct Binary Tree from Preorder and Inorder Traversal
• Convert Sorted Array to Binary Search Tree
• Count Complete Tree Nodes
• Find Bottom Left Tree Values
• Flatten Binary Tree to Linked List
• Invert Binary Tree
• Inorder Traversal of Binary Tree
• Kth Smallest Element in a BST
• Maximum Depth of Binary Tree
• Minimum Absolute Difference in BST
• Minimum Depth of Binary Tree
• Lowest Common Ancestor
• Path Sum
• Path Sum ii
• Sum of Left Leaves
• Symmetric Tree
• Validate Binary Search Tree

Two Pointers

• 4 Sum