Problem title
Difficulty
Avg time to solve

LCA of three Nodes
Easy
20 mins
Sum Of Infinite Array
Moderate
35 mins
Pair Sum
Easy
15 mins
Reverse The Array
Easy
15 mins
Sum or Product
Easy
15 mins
Two Sum
Easy
10 mins
Find Duplicate in Array
Easy
15 mins
Flower Shop
Easy
--
Sort 0 1 2
Easy
22 mins
Maximum Subarray Sum
Hard
35 mins
460

Find Duplicate in Array

Difficulty: EASY
Contributed By
Avg. time to solve
15 min
Success Rate
85%

Problem Statement

You are given an array of integers 'ARR' containing N elements. Each integer is in the range [1, N-1], with exactly one element repeated in the array.

Your task is to find the duplicate element. The duplicate element may be repeated more than twice in the error, but there will be exactly one element that is repeated in the array.

Note :

All the integers in the array appear only once except for precisely one integer which appears two or more times.

Input format:

The first line of input contains an integer ‘T’ denoting the number of test cases. Then the T test cases follow.

The first line of each test case contains an integer ‘N’, the number of elements in the array. 

The second line of each test case contains ‘N’ space-separated integers representing the elements of the array. 

Output format:

For each test case, the duplicate element of the given array is printed.

The output of each test case is printed in a separate line. 
Note :
You are not supposed to print anything; It has already been taken care of. Just implement the given function.
Constraints :
1 <= T <= 5
1 <= N <= 10^5
1 <= ARR[i] <= N - 1

Time Limit: 1 sec

Sample Input 1:

1
3
1 1 2

Sample Output 1:

1

Explanation of Sample Input 1:

1 is repeated in the array, hence function returns 1.

Sample Input 2:

3
5
1 3 4 2 2
5
3 1 3 4 2
3
1 1 1

Sample Output 2:

2
3
1
Reset Code
Full screen
copy-code
Console