Find the Duplicate Number
Given an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.
There is only one repeated number in nums; return this repeated number.
You must solve the problem without modifying the array nums and using only constant extra space.
Follow up:
- How can we prove that at least one duplicate number must exist in
nums? - Can you solve the problem in linear runtime complexity?
Example 1
Input
nums = [1,3,4,2,2]Output
2The number 2 is the only repeated number in
nums.Example 2
Input
nums = [3,1,3,4,2]Output
3The number 3 is the only repeated number in
nums.Constraints
1 <= n <= 10^5nums.length == n + 11 <= nums[i] <= n- All the integers in
numsappear only once except for precisely one integer which appears two or more times.