150 Software Engineer - DSA Interview Questions

Software Engineer - DSA Interview Questions

Remove Element

Array / String

Easy

Practice

Remove Duplicates from Sorted Array

Array / String

Easy

Practice

Remove Duplicates from Sorted Array II

Array / String

Medium

Practice

Majority Element

Array / String

Easy

Practice

Rotate Array

Array / String

Medium

Practice

Best Time to Buy and Sell Stock

Array / String

Easy

Practice

Best Time to Buy and Sell Stock II

Array / String

Medium

Practice

Jump Game

Array / String

Medium

Practice

Jump Game II

Array / String

Medium

Practice

H-Index

Array / String

Medium

Practice

Insert Delete GetRandom O(1)

Array / String

Medium

Practice

Product of Array Except Self

Array / String

Medium

Practice

Gas Station

Array / String

Medium

Practice

Candy

Array / String

Hard

Practice

Trapping Rain Water

Array / String

Hard

Practice

Roman to Integer

Array / String

Easy

Practice

Integer to Roman

Array / String

Medium

Practice

Length of Last Word

Array / String

Easy

Practice

Longest Common Prefix

Array / String

Easy

Practice

Reverse Words in a String

Array / String

Medium

Practice

Zigzag Conversion

Array / String

Medium

Practice

Find the Index of the First Occurrence in a String

Array / String

Easy

Practice

Text Justification

Array / String

Hard

Practice

Valid Palindrome

Two Pointers

Easy

Practice

Is Subsequence

Two Pointers

Easy

Practice

Two Sum II - Input Array Is Sorted

Two Pointers

Medium

Practice

Container With Most Water

Two Pointers

Medium

Practice

3Sum

Two Pointers

Medium

Practice

Minimum Size Subarray Sum

Sliding Window

Medium

Practice

Longest Substring Without Repeating Characters

Sliding Window

Medium

Practice

Substring with Concatenation of All Words

Sliding Window

Hard

Practice

Minimum Window Substring

Sliding Window

Hard

Practice

Valid Sudoku

Matrix

Medium

Practice

Spiral Matrix

Matrix

Medium

Practice

Rotate Image

Matrix

Medium

Practice

Set Matrix Zeroes

Matrix

Medium

Practice

Game of Life

Matrix

Medium

Practice

Ransom Note

Hashmap

Easy

Practice

Isomorphic Strings

Hashmap

Easy

Practice

Word Pattern

Hashmap

Easy

Practice

Valid Anagram

Hashmap

Easy

Practice

Group Anagrams

Hashmap

Medium

Practice

Two Sum

Hashmap

Easy

Practice

Happy Number

Hashmap

Easy

Practice

Contains Duplicate II

Hashmap

Easy

Practice

Longest Consecutive Sequence

Hashmap

Medium

Practice

Summary Ranges

Intervals

Easy

Practice

Merge Intervals

Intervals

Medium

Practice

Insert Interval

Intervals

Medium

Practice

Minimum Number of Arrows to Burst Balloons

Intervals

Medium

Practice

Valid Parentheses

Stack

Easy

Practice

Simplify Path

Stack

Medium

Practice

Min Stack

Stack

Medium

Practice

Evaluate Reverse Polish Notation

Stack

Medium

Practice

Basic Calculator

Stack

Hard

Practice

Linked List Cycle

Linked List

Easy

Practice

Add Two Numbers

Linked List

Medium

Practice

Merge Two Sorted Lists

Linked List

Easy

Practice

Copy List with Random Pointer

Linked List

Medium

Practice

Reverse Linked List II

Linked List

Medium

Practice

Reverse Nodes in k-Group

Linked List

Hard

Practice

Remove Nth Node From End of List

Linked List

Medium

Practice

Remove Duplicates from Sorted List II

Linked List

Medium

Practice

Rotate List

Linked List

Medium

Practice

Partition List

Linked List

Medium

Practice

LRU Cache

Linked List

Medium

Practice

Maximum Depth of Binary Tree

Binary Tree General

Easy

Practice

Same Tree

Binary Tree General

Easy

Practice

Invert Binary Tree

Binary Tree General

Easy

Practice

Symmetric Tree

Binary Tree General

Easy

Practice

Construct Binary Tree from Preorder and Inorder Traversal

Binary Tree General

Medium

Practice

Construct Binary Tree from Inorder and Postorder Traversal

Binary Tree General

Medium

Practice

Populating Next Right Pointers in Each Node II

Binary Tree General

Medium

Practice

Flatten Binary Tree to Linked List

Binary Tree General

Medium

Practice

Path Sum

Binary Tree General

Easy

Practice

Sum Root to Leaf Numbers

Binary Tree General

Medium

Practice

Binary Tree Maximum Path Sum

Binary Tree General

Hard

Practice

Binary Search Tree Iterator

Binary Tree General

Medium

Practice

Count Complete Tree Nodes

Binary Tree General

Easy

Practice

Lowest Common Ancestor of a Binary Tree

Binary Tree General

Medium

Practice

Binary Tree Right Side View

Binary Tree BFS

Medium

Practice

Average of Levels in Binary Tree

Binary Tree BFS

Easy

Practice

Binary Tree Level Order Traversal

Binary Tree BFS

Medium

Practice

Binary Tree Zigzag Level Order Traversal

Binary Tree BFS

Medium

Practice

Minimum Absolute Difference in BST

Binary Search Tree

Easy

Practice

Kth Smallest Element in a BST

Binary Search Tree

Medium

Practice

Validate Binary Search Tree

Binary Search Tree

Medium

Practice

Number of Islands

Graph General

Medium

Practice

Surrounded Regions

Graph General

Medium

Practice

Clone Graph

Graph General

Medium

Practice

Evaluate Division

Graph General

Medium

Practice

Course Schedule

Graph General

Medium

Practice

Course Schedule II

Graph General

Medium

Practice

Snakes and Ladders

Graph BFS

Medium

Practice

Minimum Genetic Mutation

Graph BFS

Medium

Practice

Word Ladder

Graph BFS

Hard

Practice

Implement Trie (Prefix Tree)

Trie

Medium

Practice

Design Add and Search Words Data Structure

Trie

Medium

Practice

Word Search II

Trie

Hard

Practice

Letter Combinations of a Phone Number

Backtracking

Medium

Practice