Add Java Code for Swapping Alternate Elements in an Array

 Question: 

You have been given an array/list(ARR) of size N. You need to swap every pair of alternate elements in the array/list.

You don't need to print or return anything, just change in the input array itself.

Ans: 

package learningJava;

import java.util.*;

public class swapAlternate {

public static int [] swapAlternate(int arr[], int size, int temp) {

for(int i = 0 ; i < size-1; i = i+2) {

temp = arr[i];

arr[i] = arr[i+1];

arr[i+1] = temp;

}

return arr;

}

//main function start from here

public static void main(String[] args) {

Scanner scan = new Scanner(System.in);

System.out.print("Enter Size of Array:");

int size = scan.nextInt();

int temp = 0;

System.out.println("Enter Array Element:");

int arr [] = new int[size];

for(int i = 0 ; i < size; i++) {

arr[i] = scan.nextInt();

}

/// Call to function

swapAlternate(arr,size,temp);

for(int i = 0 ; i < size; i++) {

System.out.print(arr[i] + " ");

}

}

}

Question: What is Swap Alternate in Java ?

Ans: 

"Swap alternate" ka matlab hota hai ki aap ek array ke alternate elements ko yaani ki har doosre element ko aapas mein swap kar dete hain. Java mein, aap ise do tareeko se kar sakte hain:

Temporary Variable Ka Istemal: Aap ek temporary variable ka istemal karke do elements ko swap kar sakte hain. Yeh tareeka kaafi straightforward hai. Aap ek element ko temporary variable mein store karke dusre element ko us jagah par rakh sakte hain aur phir temporary variable mein stored element ko dusre jagah par rakh sakte hain.

Example:

java

int temp = arr[i];

arr[i] = arr[i + 1];

arr[i + 1] = temp;

Bitwise XOR Ka Istemal: Aap bitwise XOR operator (^) ka istemal karke bhi elements ko swap kar sakte hain, lekin yeh approach advanced users ke liye hota hai. Ismein bina temporary variable ke elements ko swap kiya jata hai.

Example:

java

arr[i] = arr[i] ^ arr[i + 1];

arr[i + 1] = arr[i] ^ arr[i + 1];

arr[i] = arr[i] ^ arr[i + 1];

Yeh tareekon se aap Java mein "swap alternate" operation kar sakte hain, jisse aap ek array ke elements ko aapas mein swap kar sakte hain.