Find GCD of Two Numbers using Recursion – Java Code

Write a Java program to find GCD of two numbers using Recursion. Given two input integers, we have to write a code to find GCD of two numbers using recursion. For this program, I assume you are familiar with the concept of recursion. If you don’t know about recursion then check my previous post on recursion vs iteration.

Java Program to Find the First Non-repeated Character in a String

Write a java program to find the first non-repeated character in a string.Given an input string, we have to write a java code to find the first non-repeated character in a string.

For example –

i) Input string – java
Output – j (j is the first non-repeating character in a string)

ii) Input string – web rewrite
Output – b (b is the first non-repeating character in a string)

Java Program to Check Prime Number

Write a Java program to check prime number. Given an input integer, We have to write an efficient code to check whether a number is prime or not.

Before writing a program, let’s quickly understand what is a prime number.

Prime Number

A prime number is a number that is greater than 1 and it has no positive divisors other than 1 and itself.

For example – 3, 13, 7  is a prime number, as it’s divisible by 1 and itself. Similarly, 29, 19 etc. are also prime numbers.

6 is not a prime number as it’s divisible by 1, 2, 3 and 6.

 2 is the only even prime number.

 

How to check whether a number is prime or not in Java

Find Duplicate Elements in an Array – Java Program

Write a java program to find duplicate elements in an array. There are multiple ways through which we can find duplicate elements in an array. In this tutorial, I’ll discuss three ways to find duplicate elements in an array.
This question is also very important in terms of technical interviews.