Top Interview 150

Linked List Math Recursion

Add Two Numbers

Medium✓ Solution📹 Video

Hash Table Sliding Window String

Longest Substring Without Repeating Characters

Medium✓ Solution📹 Video

Array Binary Search Divide and Conquer

Median of Two Sorted Arrays

Hard✓ Solution📹 Video

Dynamic Programming String Two Pointers

Longest Palindromic Substring

Medium✓ Solution📹 Video

Zigzag Conversion

Medium✓ Solution📹 Video

String

Palindrome Number

Easy✓ Solution📹 Video

Math

Array Greedy Two Pointers

#11

Container With Most Water

Medium✓ Solution📹 Video

#12

Integer to Roman

Medium✓ Solution📹 Video

Hash Table Math String

#13

Roman to Integer

Easy✓ Solution📹 Video

Hash Table Math String

#14

Longest Common Prefix

Easy✓ Solution📹 Video

String Trie

Array Sorting Two Pointers

#15

3Sum

Medium✓ Solution📹 Video

Backtracking Hash Table String

#17

Letter Combinations of a Phone Number

Medium✓ Solution

#19

Remove Nth Node From End of List

Medium✓ Solution📹 Video

#20

Valid Parentheses

Easy✓ Solution📹 Video

Stack String

#21

Merge Two Sorted Lists

Easy✓ Solution📹 Video

Linked List Recursion

Backtracking Dynamic Programming String

#22

Generate Parentheses

Medium✓ Solution📹 Video

Divide and Conquer Heap (Priority Queue)Linked List+1

#23

Merge k Sorted Lists

Hard✓ Solution📹 Video

#25

Reverse Nodes in k-Group

Hard✓ Solution

Linked List Recursion

#26

Remove Duplicates from Sorted Array

Easy✓ Solution

Array Two Pointers

#27

Remove Element

Easy✓ Solution📹 Video

Array Two Pointers

String String Matching Two Pointers

#28

Find the Index of the First Occurrence in a String

Easy✓ Solution📹 Video

Hash Table Sliding Window String

#30

Substring with Concatenation of All Words

Hard✓ Solution📹 Video

#33

Search in Rotated Sorted Array

Medium✓ Solution

#34

Find First and Last Position of Element in Sorted Array

Medium✓ Solution

#35

Search Insert Position

Easy✓ Solution📹 Video

#36

Valid Sudoku

Medium✓ Solution

Array Hash Table Matrix

#39

Combination Sum

Medium✓ Solution📹 Video

Array Backtracking

Array Dynamic Programming Monotonic Stack+2

#42

Trapping Rain Water

Hard✓ Solution

Array Dynamic Programming Greedy

#45

Jump Game II

Medium✓ Solution📹 Video

#46

Permutations

Medium✓ Solution

Array Backtracking

#48

Rotate Image

Medium✓ Solution

Array Math Matrix

#49

Group Anagrams

Medium✓ Solution📹 Video

Array Hash Table Sorting+1

#50

Pow(x, n)

Medium✓ Solution📹 Video

Math Recursion

#52

N-Queens II

Hard✓ Solution📹 Video

Backtracking

Array Divide and Conquer Dynamic Programming

#53

Maximum Subarray

Medium✓ Solution📹 Video

#54

Spiral Matrix

Medium✓ Solution

Array Matrix Simulation

Array Dynamic Programming Greedy

#55

Jump Game

Medium✓ Solution📹 Video

#56

Merge Intervals

Medium✓ Solution📹 Video

Array Sorting

#57

Insert Interval

Medium✓ Solution📹 Video

Array

#58

Length of Last Word

Easy✓ Solution

String

#61

Rotate List

Medium✓ Solution

Array Dynamic Programming Matrix

#63

Unique Paths II

Medium✓ Solution

Array Dynamic Programming Matrix

#64

Minimum Path Sum

Medium✓ Solution📹 Video

#66

Plus One

Easy✓ Solution📹 Video

Array Math

#67

Add Binary

Easy✓ Solution

Bit Manipulation Math Simulation+1

#68

Text Justification

Hard✓ Solution

Array Simulation String

#69

Sqrt(x)

Easy✓ Solution📹 Video

Binary Search Math

Dynamic Programming Math Memoization

#70

Climbing Stairs

Easy✓ Solution📹 Video

#71

Simplify Path

Medium✓ Solution📹 Video

Stack String

Dynamic Programming String

#72

Edit Distance

Medium✓ Solution📹 Video

#73

Set Matrix Zeroes

Medium✓ Solution📹 Video

Array Hash Table Matrix

Array Binary Search Matrix

#74

Search a 2D Matrix

Medium✓ Solution📹 Video

Hash Table Sliding Window String

#76

Minimum Window Substring

Hard✓ Solution

#77

Combinations

Medium✓ Solution📹 Video

Backtracking

#79

Word Search

Medium✓ Solution📹 Video

Array Backtracking Matrix+1

#80

Remove Duplicates from Sorted Array II

Medium✓ Solution📹 Video

Array Two Pointers

#82

Remove Duplicates from Sorted List II

Medium✓ Solution📹 Video

#86

Partition List

Medium✓ Solution

Array Sorting Two Pointers

#88

Merge Sorted Array

Easy✓ Solution📹 Video

#92

Reverse Linked List II

Medium✓ Solution📹 Video

Linked List

Dynamic Programming String

#97

Interleaving String

Medium✓ Solution📹 Video

Binary Search Tree Binary Tree Depth-First Search+1

#98

Validate Binary Search Tree

Medium✓ Solution📹 Video

Binary Tree Breadth-First Search Depth-First Search+1

#100

Same Tree

Easy✓ Solution📹 Video

Binary Tree Breadth-First Search Depth-First Search+1

#101

Symmetric Tree

Easy✓ Solution📹 Video

Binary Tree Breadth-First Search Tree

#102

Binary Tree Level Order Traversal

Medium✓ Solution

Binary Tree Breadth-First Search Tree

#103

Binary Tree Zigzag Level Order Traversal

Medium✓ Solution

Binary Tree Breadth-First Search Depth-First Search+1

#104

Maximum Depth of Binary Tree

Easy✓ Solution📹 Video

#105

Construct Binary Tree from Preorder and Inorder Traversal

Medium✓ Solution📹 Video

Array Binary Tree Divide and Conquer+2

#106

Construct Binary Tree from Inorder and Postorder Traversal

Medium✓ Solution

Array Binary Tree Divide and Conquer+2

#108

Convert Sorted Array to Binary Search Tree

Easy✓ Solution📹 Video

Array Binary Search Tree Binary Tree+2

Binary Tree Breadth-First Search Depth-First Search+1

#112

Path Sum

Easy✓ Solution📹 Video

Binary Tree Depth-First Search Linked List+2

#114

Flatten Binary Tree to Linked List

Medium✓ Solution📹 Video

Binary Tree Breadth-First Search Depth-First Search+2

#117

Populating Next Right Pointers in Each Node II

Medium✓ Solution📹 Video

Array Dynamic Programming

#120

Triangle

Medium✓ Solution📹 Video

Array Dynamic Programming

#121

Best Time to Buy and Sell Stock

Easy✓ Solution📹 Video

Array Dynamic Programming Greedy

#122

Best Time to Buy and Sell Stock II

Medium✓ Solution📹 Video

Array Dynamic Programming

#123

Best Time to Buy and Sell Stock III

Hard✓ Solution

Binary Tree Depth-First Search Dynamic Programming+1

#124

Binary Tree Maximum Path Sum

Hard✓ Solution

#125

Valid Palindrome

Easy✓ Solution

String Two Pointers

Breadth-First Search Hash Table String

#127

Word Ladder

Hard✓ Solution📹 Video

Array Hash Table Union Find

#128

Longest Consecutive Sequence

Medium✓ Solution📹 Video

Binary Tree Depth-First Search Tree

#129

Sum Root to Leaf Numbers

Medium✓ Solution

Array Breadth-First Search Depth-First Search+2

#130

Surrounded Regions

Medium✓ Solution

Breadth-First Search Depth-First Search Graph+1

#133

Clone Graph

Medium✓ Solution

#134

Gas Station

Medium✓ Solution📹 Video

Array Greedy

#135

Candy

Hard✓ Solution📹 Video

Array Greedy

#136

Single Number

Easy✓ Solution

Array Bit Manipulation

#137

Single Number II

Medium✓ Solution📹 Video

Array Bit Manipulation

#138

Copy List with Random Pointer

Medium✓ Solution📹 Video

Hash Table Linked List

#139

Word Break

Medium✓ Solution📹 Video

Array Dynamic Programming Hash Table+3

Hash Table Linked List Two Pointers

#141

Linked List Cycle

Easy✓ Solution📹 Video

#146

LRU Cache

Medium✓ Solution📹 Video

Design Doubly-Linked List Hash Table+1

Divide and Conquer Linked List Merge Sort+2

#148

Sort List

Medium✓ Solution

#149

Max Points on a Line

Hard✓ Solution📹 Video

Array Geometry Hash Table+1

#150

Evaluate Reverse Polish Notation

Medium✓ Solution

Array Math Stack

#151

Reverse Words in a String

Medium✓ Solution

String Two Pointers

#153

Find Minimum in Rotated Sorted Array

Medium✓ Solution

#155

Min Stack

Medium✓ Solution

Design Stack

#162

Find Peak Element

Medium✓ Solution📹 Video