Minimum Number of Increments on Subarrays to

lcpy gen -n 1526   # by problem number
lcpy gen -s minimum_number_of_increments_on_subarrays_to_form_a_target_array   # by problem name

Input: target = [1,2,3,2,1]
Output: 3
Explanation: We need at least 3 operations to form the target array from the initial array.
[0,0,0,0,0] increment 1 from index 0 to 4 (inclusive).
[1,1,1,1,1] increment 1 from index 1 to 3 (inclusive).
[1,2,2,2,1] increment 1 at index 2.
[1,2,3,2,1] target array is formed.

Input: target = [3,1,1,2]
Output: 4
Explanation: [0,0,0,0] -> [1,1,1,1] -> [1,1,1,2] -> [2,1,1,2] -> [3,1,1,2]

Input: target = [3,1,5,4,2]
Output: 7
Explanation: [0,0,0,0,0] -> [1,1,1,1,1] -> [2,1,1,1,1] -> [3,1,1,1,1] -> [3,1,2,2,2] -> [3,1,3,3,2] -> [3,1,4,4,2] -> [3,1,5,4,2]

class Solution:
    # Time: O(n)
    # Space: O(1)
    def min_number_operations(self, target: list[int]) -> int:
        operations = 0
        prev = 0
        for value in target:
            if value > prev:
                operations += value - prev
            prev = value
        return operations