lintcode-515-房屋染色

public class Solution {
    /**
     * @param costs: n x 3 cost matrix
     * @return: An integer, the minimum cost to paint all houses
     */
    public int minCost(int[][] costs) {
        // write your code here
        int n = costs.length;
        if(n==0)
            return 0;
        int[][] dp = new int[n][3];
        dp[0][0]=costs[0][0];
        dp[0][1]=costs[0][1];
        dp[0][2]=costs[0][2];
        for(int i=1;i<n;++i){
            for(int j=0;j<3;++j){
                dp[i][j]=Integer.MAX_VALUE;
                for(int k=0;k<3;++k) {
                    if (k != j) {
                        dp[i][j] = Math.min(dp[i][j], dp[i - 1][k]+costs[i][j]);
                    }
                }
            }
        }
        return Math.min(dp[n-1][0],Math.min(dp[n-1][1],dp[n-1][2]));
    }
}