Solving Find the Duplicate Number in go. Please try yourself first to solve the problem and submit your implementation to LeetCode before looking into solution.

Problem Description

Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume that there is only one duplicate number, find the duplicate one.

Example 1:

Input: [1,3,4,2,2]
Output: 2

Example 2:

Input: [3,1,3,4,2]
Output: 3


  • You must not modify the array (assume the array is read only).
  • You must use only constant, O(1) extra space.
  • Your runtime complexity should be less than O(n^2).
  • There is only one duplicate number in the array, but it could be repeated more than once.

See the full details of the problem Find the Duplicate Number at LeetCode

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