The colorful street

the_colorful_street.py

import sys
def find_cost():
    testcases = int(sys.stdin.readline())
    for x in range(testcases):
        num_of_houses = int(sys.stdin.readline())
        cost_of_color = cost_table(num_of_houses)
        dp = [[0 for i in range(3)] for i in range(num_of_houses)]
        for i in range(3):
            dp[0][i] = cost_of_color[0][i]
 
        for i in range(1, num_of_houses):
            dp[i][0] = min( dp[i-1][1] , dp[i-1][2] ) + cost_of_color[i][0]
            dp[i][1] = min( dp[i-1][0] , dp[i-1][2] ) + cost_of_color[i][1]
            dp[i][2] = min( dp[i-1][0] , dp[i-1][1] ) + cost_of_color[i][2]
        print min(min(dp[num_of_houses-1][0], dp[num_of_houses-1][1]) , dp[num_of_houses-1][2])
    return 0
 
def cost_table(num_of_houses):
    '''creates a list of n list where n is num_of_houses'''
    cost_of_color = [[0 for i in range(3)] for i in range(num_of_houses)]
    for i in range(num_of_houses):
        cost_of_color[i] = map(int, (sys.stdin.readline()).split())
    return cost_of_color
 
 
find_cost()