2170 - Minimum Operations to Make the Array Alternating\.

Medium

You are given a 0-indexed array nums consisting of n positive integers.

The array nums is called alternating if:

• nums[i - 2] == nums[i], where 2 <= i <= n - 1.

• nums[i - 1] != nums[i], where 1 <= i <= n - 1.

In one operation , you can choose an index i and change nums[i] into any positive integer.

Return the minimum number of operations required to make the array alternating.

Example 1:

Input: nums = 3,1,3,2,4,3

Output: 3

Explanation:

One way to make the array alternating is by converting it to 3,1,3, **1** , **3** , **1** .

The number of operations required in this case is 3.

It can be proven that it is not possible to make the array alternating in less than 3 operations.

Example 2:

Input: nums = 1,2,2,2,2

Output: 2

Explanation:

One way to make the array alternating is by converting it to 1,2, **1** ,2, **1** .

The number of operations required in this case is 2.

Note that the array cannot be converted to **2** ,2,2,2,2 because in this case nums0 == nums1 which violates the conditions of an alternating array.

Constraints:

• <code>1 <= nums.length <= 10⁵</code>

• <code>1 <= numsi<= 10⁵</code>