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Find Duplicate in Array
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15 mins
682 upvotes
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Find Duplicate in Array

Contributed by
Dhruv Sharma
Easy
Avg time to solve 15 mins
Success Rate 85 %
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682 upvotes

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

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
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