Hash Table Coding Problems

Understand hashing and key-value operations

719
Total Problems
168
Easy
418
Medium
127
Hard
Start Practicing
key → valkey → val

Master DSA Topics - February, 2026

Practice problems across 75+ categories

Hash Table Coding Problems

Practice problems frequently asked at Hash Table 719 problems | 168 Easy | 418 Medium | 127 Hard

# Problem Difficulty Topics
136 Count Unique Characters of All Substrings of a Given String Hard
Hash TableStringDynamic Programming
137 Count Vowel Substrings of a String Easy
Hash TableString
138 Count Words Obtained After Adding a Letter Medium
ArrayHash TableString
139 Count Zero Request Servers Medium
ArrayHash TableSliding Window
140 Counting Elements Easy
ArrayHash Table
141 Cousins in Binary Tree II Medium
Hash TableTreeDepth-First Search
142 Create Binary Tree From Descriptions Medium
ArrayHash TableTree
143 Custom Sort String Medium
Hash TableStringSorting
144 Data Stream as Disjoint Intervals Hard
Hash TableBinary SearchUnion Find
145 Decode the Message Easy
Hash TableString
146 Degree of an Array Easy
ArrayHash Table
147 Delete and Earn Medium
ArrayHash TableDynamic Programming
148 Delete Duplicate Folders in System Hard
ArrayHash TableString
149 Delete Nodes And Return Forest Medium
ArrayHash TableTree
150 Delete Nodes From Linked List Present in Array Medium
ArrayHash TableLinked List
Showing 136-150 of 719
1 ... 8 9 10 11 12 ... 48

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.