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Problem

Submissions

Single Number

Contributed by

Naresh

Easy

0/40

Avg time to solve 10 mins

Success Rate 90 %

18 upvotes

Problem Statement

You are given an array A of length N, where N is always an odd integer. There are (N-1)/2 elements in the array that occur twice and one element which occurs once. Your task is to find the only element that occurs once in the array.

Note: There are (N-1)/2+1 elements that are unique in the array.

Detailed explanation ( Input/output format, Notes, Constraints, Images )

Input Format:

The first line of the input contains ‘T’ denoting the number of test cases.

The first line of each test case contains an integer ‘N’, representing the length of the array.

The second line of each test case contains N space-separated integers of the array A.

Output Format:

For each test case, print the only integer which occurs once in the array.
The output of each test case is printed on a new line.

Note:

You do not need to print anything, it has already been taken care of. Just implement the given function.

Constraints:

1 <= T <= 50
1 <= N <= 10^4
-10^6 <=  A[i] <=10^6

Where T denotes the number of test cases and N denotes the length of array A[].

Time Limit: 1 sec

Sample Input 1:

2
7
7 3 5 4 5 3 4
9
5 6 9 6 1 9 1 5 3

Sample Output 1:

7
3

Explanation For Sample Input 1:

In the first test case the integers 3, 4, 5 occur twice and only the integer 7 occurs once.

In the second test case the integers 1, 5, 6, 9 occur twice and only the integer 3 occurs once.

Sample Input 2:

Sample Output 2:

5
9
9

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