Minimum Total Increment to Make Array Non-decreasing (Range Increment Operations)

Given an integer sequence A = [a1, a2, ..., an] of length n, you may perform any number of operations. In each operation: Choose a closed interval [i, j] (1 <= i <= j <= n) Choose a positive integer x Increase every element a_k for i <= k <= j by x After all operations, the sequence must be non-decreasing: a_i <= a_{i+1}. Minimize the sum of all chosen increments x across operations: minimize Σ x. Return this minimum value. Constraints 1 <= n <= 2*10^5 -10^9 <= a_i <= 10^9 Example Input: [3, 1, 2] Output: 3 Example Input 3 3 1 2 Output 3