3576 - Transform Array to All Equal Elements.

Medium

You are given an integer array nums of size n containing only 1 and -1, and an integer k.

You can perform the following operation at most k times:

• Choose an index i (0 <= i < n - 1), and multiply both nums[i] and nums[i + 1] by -1.

Note that you can choose the same index i more than once in different operations.

Return true if it is possible to make all elements of the array equal after at most k operations, and false otherwise.

Example 1:

Input: nums = 1,-1,1,-1,1, k = 3

Output: true

Explanation:

We can make all elements in the array equal in 2 operations as follows:

• Choose index i = 1, and multiply both nums[1] and nums[2] by -1. Now nums = [1,1,-1,-1,1].

• Choose index i = 2, and multiply both nums[2] and nums[3] by -1. Now nums = [1,1,1,1,1].

Example 2:

Input: nums = -1,-1,-1,1,1,1, k = 5

Output: false

Explanation:

It is not possible to make all array elements equal in at most 5 operations.

Constraints:

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

• nums[i] is either -1 or 1.

• 1 <= k <= n