Find Unique Number in Array Java , XOR

 Question:  WAP to find unique number in Array Java

package aRray;

import java.util.*;

public class practicalArray {

public static void main(String[] args) {

Scanner scan = new Scanner(System.in);

// Step 1: Input size of the array from the user

int size = scan.nextInt();

// Step 2: Create an integer array of the specified size

int [] arr = new int[size];

// Step 3: Initialize 'res' with the first element of the array

int res = arr[0];

// Step 4: Loop to read array elements and find the unique number

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

// Read an integer from the user and store it in the array

arr[i] = scan.nextInt();

// Step 5: Use XOR (^) operation to find the unique number

res = res ^ arr[i];

}

// Step 6: Print the unique number

System.out.println(res);

}

}

**Step 1:** `int size = scan.nextInt();`

   - Yahan par aap user se input le rahe hain. `size` variable mein aap user dwara di gayi array ki size ko store kar rahe hain. Isse aap code ke shuru mein array ki size ko define kar sakte hain.

**Step 2:** `int [] arr = new int[size];`

   - Ab aap ek integer array `arr` create kar rahe hain, jiska size `size` variable mein store kiya gaya hai. Is array mein aapke array ke elements store honge.

**Step 3:** `int res = arr[0];`

   - `res` naam ka ek variable initialize kiya gaya hai, aur ismein pehle array element `arr[0]` ko store kiya gaya hai. Pehla element `res` ke saath XOR operation ke liye initial value ke roop mein istemal hoga.

**Step 4:** `for(int i = 1; i < size; i++) { ... }`

   - `for` loop ka upyog array ke elements ko padhne aur unique number ko nikalne ke liye kiya gaya hai. Loop `i` ko 1 se lekar `size - 1` tak chalayega, kyun ki pehla element `res` ke saath XOR ho chuka hai.

**Step 5:** `res = res ^ arr[i];`

   - Is line mein aap XOR (`^`) operation ka istemal karke unique number ko dhundh rahe hain. Har bar ek naya array element `arr[i]` `res` ke saath XOR ho raha hai. Isse duplicate elements ek dusre ko cancel kar dete hain, aur unique number `res` mein bachta hai.

**Step 6:** `System.out.println(res);`

   - Akhir mein, unique number `res` ko console par print kiya jata hai.

XOR (Exclusive OR) Kya Hai?

XOR ek binary operation hai, jo do bits ke beech mein compare karta hai. XOR keval do situations mein true (1) deta hai:

Jab dono bits alag-alag hote hain (ek true aur ek false).

Dono bits barabar hote hain (dono false).

XOR Ka Use:

Unique Number Dhundhna: Is code mein, XOR operation ka use kiya gaya hai unique number dhundhne ke liye. Jab aap ek number ko do baar XOR karte hain, to woh original number par aa jata hai, lekin agar aap kisi dusre number ke sath XOR karte hain, to unique number nikalta hai. Isi logic ko istemal karke hamne array ke elements mein se unique number nikala hai.

XOR Ke Prakar:

XOR ke do prakar hote hain:

Bitwise XOR: Yeh operation bit-wise hota hai, matlab har bit ke sath alag-alag compare hota hai. Example: 0 XOR 0 = 0, 0 XOR 1 = 1, 1 XOR 0 = 1, aur 1 XOR 1 = 0.

Logical XOR: Yeh operation boolean values ke sath kaam karta hai. Example: false XOR false = false, false XOR true = true, true XOR false = true, aur true XOR true = false