Master DSA Topics - January, 2026

Practice problems across 75+ categories

All Coding Problems

Practice coding problems across all companies and topics 3600 problems | 879 Easy | 1856 Medium | 842 Hard

# Problem Difficulty Topics
301 Change the Root of a Binary Tree Medium
TreeDepth-First SearchBinary Tree
302 Cheapest Flights Within K Stops Medium
Dynamic ProgrammingDepth-First SearchBreadth-First Search
303 Check Array Formation Through Concatenation Easy
ArrayHash Table
304 Check Balanced String Easy
String
305 Check Completeness of a Binary Tree Medium
TreeBreadth-First SearchBinary Tree
306 Check Distances Between Same Letters Easy
ArrayHash TableString
307 Check for Contradictions in Equations Hard
ArrayDepth-First SearchUnion Find
308 Check If a Number Is Majority Element in a Sorted Array Easy
ArrayBinary Search
309 Check if a Parentheses String Can Be Valid Medium
StringStackGreedy
310 Check If a String Can Break Another String Medium
StringGreedySorting
311 Check If a String Contains All Binary Codes of Size K Medium
Hash TableStringBit Manipulation
312 Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree Medium
TreeDepth-First SearchBreadth-First Search
313 Check if a String Is an Acronym of Words Easy
ArrayString
314 Check If a Word Occurs As a Prefix of Any Word in a Sentence Easy
Two PointersStringString Matching
315 Check If All 1's Are at Least Length K Places Away Easy
Array
Showing 301-315 of 3600
1 ... 19 20 21 22 23 ... 240

Tutorials Library

Master any technology with our largest free online Library. Browse through 500+ tutorials across 10+ categories.

Python

Python Tutorial

Java

Java Tutorial

JavaScript

JavaScript

C++

C++ Tutorial

C#

C# Tutorial

Go

Go Tutorial

Rust

Rust Tutorial

TypeScript

TypeScript

Swift

Swift Tutorial

Kotlin

Kotlin Tutorial

Ruby

Ruby Tutorial

PHP

PHP Tutorial

C

C Tutorial

Scala

Scala Tutorial

Perl

Perl Tutorial

R

R Tutorial

Dart

Dart Tutorial

Lua

Lua Tutorial

MATLAB

MATLAB

Haskell

Haskell

Developer Toolbox

Powerful online tools to boost your productivity

public class MyFirstJavaProgram { Edit & Run

   /* This is my first java program.
    * This will print 'Hello, World!' as the output
    */

   public static void main(String []args) {
      System.out.println("Hello, World!"); // prints
   }
}

Start Coding in Seconds

Coding Ground For Developers

Code, Edit, Run and Share

Ignite your coding potential on Coding Ground - an immersive online platform for hands-on learning, collaboration, and skill development.