There are a row of n houses, each house can be painted with one of the k colors. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two adjacent houses have the same color.
The cost of painting each house with a certain color is represented by a n x k
cost matrix. For example, costs[0][0] is the cost of painting house 0 with
color 0; costs[1][2] is the cost of painting house 1 with color 2, and so on...
Find the minimum cost to paint all houses.
Note:
All costs are positive integers.
Example:
Input: [[1,5,3],[2,9,4]] Output: 5 Explanation: Paint house 0 into color 0, paint house 1 into color 2. Minimum cost: 1 + 4 = 5; Or paint house 0 into color 2, paint house 1 into color 0. Minimum cost: 3 + 2 = 5.
Follow up:
Could you solve it in O(nk) runtime?