lintcode

class Solution {
public:
    /*
     * @param costs: n x 3 cost matrix
     * @return: An integer, the minimum cost to paint all houses
     */
     const int inf = 0x3f3f3f3f;
     vector<vector<int> > dp;
    int minCost(vector<vector<int>> &costs) {
        // write your code here'
        if(costs.size() == 0) return 0;
        dp.resize(costs.size(), vector<int>(3,inf));
        for(int i = 0; i < costs.size(); ++i){
                for(int j = 0; j < 3; ++j){
                        if(i == 0){
                                dp[i][j] = costs[i][j];
                        } else {
                                vector<int> tmp = color(j);
                                dp[i][j] = min(dp[i-1][tmp[0]], dp[i-1][tmp[1]]) + costs[i][j];
                        }
                }
        }
        return min(dp[costs.size() - 1][0], min(dp[costs.size() - 1][1], dp[costs.size() - 1][2]));
    }
    vector<int> color(int x){
        vector<int> y;
        if(x == 0){
                y.push_back(1);
                y.push_back(2);
                return y;
        } else if(x == 1){
                y.push_back(0);
                y.push_back(2);
                return y;
        } else {
                y.push_back(1);
                y.push_back(0);
                return y;
        }
    }
};