You are given an array ‘ARR’ of size ‘N’ containing each number between 1 and ‘N’ - 1 at least once. There is a single integer value that is present in the array twice. Your task is to find the duplicate integer value present in the array.
For example:
Consider ARR = [1, 2, 3, 4, 4], the duplicate integer value present in the array is 4. Hence, the answer is 4 in this case.
Note :
A duplicate number is always present in the given array.
The first line of the input contains an integer, 'T,’ denoting the number of test cases.
The first line of each test case contains a single integer, 'N', denoting the number of elements in the array.
The second line of each test case contains 'N' space-separated integers denoting the elements of the array 'ARR'.
For each test case, print a single integer - the duplicate element in the array.
Print the output of each test case in a separate line.
Constraints:
1 <= T <= 10
2 <= N <= 10 ^ 5
1 <= ARR[i] <= N - 1
Where 'T' denotes the number of test cases, 'N' denotes the number of elements in the array, and 'ARR[i]' denotes the 'i-th' element of the array 'ARR'.
Time limit: 1 sec
Sample Input 1:
2
5
4 2 1 3 1
7
6 3 1 5 4 3 2
Sample Output 1:
1
3
Explanation of sample input 1:
For the first test case,
The duplicate integer value present in the array is 1. Hence, the answer is 1 in this case.
For the second test case,
The duplicate integer value present in the array is 3. Hence, the answer is 3 in this case.
Sample Input 2:
2
6
5 1 2 3 4 2
9
8 7 2 5 4 7 1 3 6
Sample Output 2:
2
7