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 an n x k cost matrix costs.
For example, costs is the cost of painting house 0 with color 0; costs is the cost of painting house 1 with color 2, and so on…
Return the minimum cost to paint all houses.
Input: costs = [[1,5,3],[2,9,4]]
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.