Minimum Pair Removal to Sort Array II
Provided an array nums, you can perform the following operation any number of times:
-
Select the adjacent pair with the minimum sum in
nums. If multiple such pairs exist, choose the leftmost one. -
Replace the pair with their sum.
Produce the minimum number of operations needed to make the array non-decreasing.
An array is said to be non-decreasing if each element is greater than or equal to its previous element (if it exists).
Input: nums = [5,2,3,1]
Output: 2
Explanation:
-
The pair
(3,1)has the minimum sum of 4. After replacement,nums = [5,2,4]. -
The pair
(2,4)has the minimum sum of 6. After replacement,nums = [5,6].
The array nums became non-decreasing in two operations.
Input: nums = [1,2,2]
Output: 0
Explanation: The array nums is already sorted.
Constraints
1 <= nums.length <= 10^5-10^9 <= nums[i] <= 10^9
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