256. Paint House

public class Solution {
    public int minCost(int[][] costs) {
        if(costs.length==0||costs==null) 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][1],costs[i-1][0]);
        }
        int n=costs.length-1;
        return Math.min(Math.min(costs[n][0],costs[n][1]),costs[n][2]);
    }
}