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 - January, 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
31 Buddy Strings Easy
Hash TableString
32 Bulls and Cows Medium
Hash TableStringCounting
33 Bus Routes Hard
ArrayHash TableBreadth-First Search
34 Calculate Score After Performing Instructions Medium
ArrayHash TableString
35 Can Convert String in K Moves Medium
Hash TableString
36 Can Make Palindrome from Substring Medium
ArrayHash TableString
37 Card Flipping Game Medium
ArrayHash Table
38 Change Minimum Characters to Satisfy One of Three Conditions Medium
Hash TableStringCounting
39 Check Array Formation Through Concatenation Easy
ArrayHash Table
40 Check Distances Between Same Letters Easy
ArrayHash TableString
41 Check If a String Contains All Binary Codes of Size K Medium
Hash TableStringBit Manipulation
42 Check if All Characters Have Equal Number of Occurrences Easy
Hash TableStringCounting
43 Check if All the Integers in a Range Are Covered Easy
ArrayHash TablePrefix Sum
44 Check if an Array Is Consecutive Easy
ArrayHash TableSorting
45 Check if Any Element Has Prime Frequency Easy
ArrayHash TableMath
Showing 31-45 of 719
1 2 3 4 5 ... 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.