Python Array Change
def array_change(a: list[int]) -> int:
    moves = 0
    for k in range(len(a) - 1):
        if a[k] >= a[k + 1]:
            diff = a[k] - a[k + 1] + 1
            a[k + 1] += diff
            moves += diff
    return moves

This moves left to right and bumps values only when needed so the array becomes strictly increasing.