CodingHardcod-g943

Subject Dynamic programming 2dLevel Senior–Staff~35 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

There are n houses in a row, each to be painted one of k colors, with cost[i][c] the cost of painting house i color c. No two adjacent houses may share a color. Return the minimum total painting cost. There are at most 100 houses and at most 20 colors. Aim for time better than O(n*k^2).

Implement

min_paint_cost(cost: list[list[int]]) → int

Examples

in[[[1,5,3],[2,9,4]]]out5

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.