3191 - Minimum Operations to Make Binary Array Elements Equal to One I\.

Medium

You are given a binary array nums.

You can do the following operation on the array any number of times (possibly zero):

• Choose any 3 consecutive elements from the array and flip all of them.

Flipping an element means changing its value from 0 to 1, and from 1 to 0.

Return the minimum number of operations required to make all elements in nums equal to 1. If it is impossible, return -1.

Example 1:

Input: nums = 0,1,1,1,0,0

Output: 3

Explanation: We can do the following operations:

• Choose the elements at indices 0, 1 and 2. The resulting array is <code>nums = <ins> **1** </ins>,<ins> **0** </ins>,<ins> **0** </ins>,1,0,0</code>.

• Choose the elements at indices 1, 2 and 3. The resulting array is <code>nums = 1,<ins> **1** </ins>,<ins> **1** </ins>, **<ins>0</ins>** ,0,0</code>.

• Choose the elements at indices 3, 4 and 5. The resulting array is <code>nums = 1,1,1, **<ins>1</ins>** ,<ins> **1** </ins>,<ins> **1** </ins></code>.

Example 2:

Input: nums = 0,1,1,1

Output: \-1

Explanation: It is impossible to make all elements equal to 1.

Constraints:

• <code>3 <= nums.length <= 10⁵</code>

• 0 <= nums[i] <= 1