There are a row ofnhouses, each house can be painted with one of the three colors: red, blue or green. 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 anx3cost matrix. For example,costs[0][0]is the cost of painting house 0 with color red;costs[1][2]is the cost of painting house 1 with color green, and so on... Find the minimum cost to paint all houses.

Note:
All costs are positive integers.

class Solution {
    public int minCost(int[][] costs) {
        if(costs == null || costs.length == 0)
            return 0;

        for(int i = 1; i < costs.length; i++) {
            costs[i][0] += Math.min(costs[i - 1][1], costs[i - 1][2]);
            costs[i][1] += Math.min(costs[i - 1][0], costs[i - 1][2]);
            costs[i][2] += Math.min(costs[i - 1][0], costs[i - 1][1]);
        }

        int res = costs[costs.length - 1][0];
        res = Math.min(res, costs[costs.length - 1][1]);
        res = Math.min(res, costs[costs.length - 1][2]);
        return res;
    }
}