CodingHardcod-g491

Subject Slope trickLevel Senior–Staff~35 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given an integer array `a`, you may increment or decrement any element by 1 at a cost of 1 per unit. Find the minimum total cost to make the array non-decreasing (a[0] <= a[1] <= ... <= a[n-1]). Return that minimum cost.

Implement

min_cost_non_decreasing(a: list[int]) → int

Examples

in[[3,2,1]]out2

What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

Learn the concepts

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.