There are a row of n houses, each house can be painted with one of the k colors. 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 a n x k cost matrix. For example, costs[0][0] is the cost of painting house 0 with color 0; costs[1][2] is the cost of painting house 1 with color 2, and so on... Find the minimum cost to paint all houses.
Notice
All costs are positive integers.
Example
Given n = 3, k = 3, costs = [[14,2,11],[11,14,5],[14,3,10]] return 10
house 0 is color 2, house 1 is color 3, house 2 is color 2, 2 + 5 + 3 = 10
[LintCode] Paint House II 粉刷房子之二
原文：http://www.cnblogs.com/grandyang/p/5448505.html