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Find the Duplicate Number

Hard

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Find the duplicate number in array with n+1 integers where each is between 1 and n.

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

Hint 3

Find cycle start point

Code Editor

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