Medium
You are given an integer array nums of length n.
In one operation, you may choose any nums[l..r] and increase each element in that subarray by x, where x is any positive integer.
Return the minimum possible sum of the values of x across all operations required to make the array non-decreasing.
An array is non-decreasing if nums[i] <= nums[i + 1] for all 0 <= i < n - 1.
Example 1:
Input: nums = [3,3,2,1]
Output: 2
Explanation:
One optimal set of operations:
- Choose subarray
[2..3]and addx = 1resulting in[3, 3, 3, 2] - Choose subarray
[3..3]and addx = 1resulting in[3, 3, 3, 3]
The array becomes non-decreasing, and the total sum of chosen x values is 1 + 1 = 2.
Example 2:
Input: nums = [5,1,2,3]
Output: 4
Explanation:
One optimal set of operations:
- Choose subarray
[1..3]and addx = 4resulting in[5, 5, 6, 7]
The array becomes non-decreasing, and the total sum of chosen x values is 4.
Constraints:
1 <= n == nums.length <= 1051 <= nums[i] <= 109