[LeetCode] 256. Paint House

 Problem : https://leetcode.com/problems/paint-house/

Let the state dp[i] as minimum cost by using color i to paint current house. Because current state is decided by the last state. This problem can be solved by DP solution. 

class Solution:
    def minCost(self, costs: List[List[int]]) -> int:
        N = len(costs)
        dp = costs[0]
        
        for i in range(1, N):
            dp = [min(dp[1], dp[2]) + costs[i][0], min(dp[0], dp[2]) + costs[i][1], min(dp[0], dp[1]) + costs[i][2]]
        
        return min(dp)