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Find the Duplicate Number

Medium

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Given an array of n+1 integers where each integer is between 1 and n, find the duplicate number.

Sample Input:

[1,3,4,2,2]

Sample Output:

Hints

Hint 1

Use Floyd's Tortoise and Hare algorithm

Hint 2

Treat array as linked list where value points to index

Hint 3

Find intersection point and then find cycle entrance

Code Editor

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