Minimum Pair Removal to Sort Array I
Given 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.
Return 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.
Example 1
Input
nums = [5,2,3,1]Output
2The pair
(3, 1) is replaced first, then (2, 4) is replaced, making nums = [5, 6] non-decreasing after two operations.Example 2
Input
nums = [1,2,2]Output
0The array
nums is already sorted.Constraints
- 1 <= nums.length <= 50
- -1000 <= nums[i] <= 1000