Bit Manipulation Challenges - Hacker Rank Solution

There are N$N$ integers in an array A$A$. All but one integer occur in pairs. Your task is to find the number that occurs only once.

Input Format
The first line of the input contains an integer N$N$, indicating the number of integers. The next line contains N$N$ space-separated integers that form the array A$A$.

Constraints
1≤N<100$1\le N<100$
N$N$ % 2=1$2=1$ (N$N$ is an odd number)
0≤A[i]≤100,∀i∈[1,N]$0\le A[i]\le 100,\forall i\in [1,N]$
Output Format
Output S$S$, the number that occurs only once.
Sample Input:1

1
1

Sample Output:1

1

Sample Input:2

3
1 1 2

Sample Output:2

2

Sample Input:3

5
0 0 1 2 1

Sample Output:3

2

Explanation
In the first input, we see only one element (1) and that element is the answer.
In the second input, we see three elements; 1 occurs at two places and 2 only once. Thus, the answer is 2.
In the third input, we see five elements. 1 and 0 occur twice. The element that occurs only once is 2.

Bit Manipulation Challenges -  Hacker Rank Solution 

import java.io.*;
import java.util.*;

public class Solution {

    public static void main(String[] args) {
     Scanner key = new Scanner(System.in);
     int N = key.nextInt();
     int[] A = new int [N];
     for(int n = 0; n < N; n++){
         A[n] = key.nextInt();
     }
     boolean exist;
     for(int i = 0; i < N; i++){
        exist = false;
        for(int n = 0; n < N; n++){
           if(A[i] == A[n] && n != i){
               exist = true;
        }
     }
     if(!exist){
         System.out.println(A[i]);
         break;
     }
  }
}
}

Bit Manipulation Challenges -  Hacker Rank Solution