Package g1401_1500.s1473_paint_house_iii

Class Solution

java.lang.Object

g1401_1500.s1473_paint_house_iii.Solution

public class Solution
extends Object

1473 - Paint House III.

Hard

There is a row of m houses in a small city, each house must be painted with one of the n colors (labeled from 1 to n), some houses that have been painted last summer should not be painted again.

A neighborhood is a maximal group of continuous houses that are painted with the same color.

• For example: houses = [1,2,2,3,3,2,1,1] contains 5 neighborhoods [{1}, {2,2}, {3,3}, {2}, {1,1}].

Given an array houses, an m x n matrix cost and an integer target where:

• houses[i]: is the color of the house i, and 0 if the house is not painted yet.
• cost[i][j]: is the cost of paint the house i with the color j + 1.

Return the minimum cost of painting all the remaining houses in such a way that there are exactly target neighborhoods. If it is not possible, return -1.

Example 1:

Input: houses = [0,0,0,0,0], cost = [[1,10],[10,1],[10,1],[1,10],[5,1]], m = 5, n = 2, target = 3

Output: 9

Explanation: Paint houses of this way [1,2,2,1,1]

This array contains target = 3 neighborhoods, [{1}, {2,2}, {1,1}].

Cost of paint all houses (1 + 1 + 1 + 1 + 5) = 9.

Example 2:

Input: houses = [0,2,1,2,0], cost = [[1,10],[10,1],[10,1],[1,10],[5,1]], m = 5, n = 2, target = 3

Output: 11

Explanation: Some houses are already painted, Paint the houses of this way [2,2,1,2,2]

This array contains target = 3 neighborhoods, [{2,2}, {1}, {2,2}].

Cost of paint the first and last house (10 + 1) = 11.

Example 3:

Input: houses = [3,1,2,3], cost = [[1,1,1],[1,1,1],[1,1,1],[1,1,1]], m = 4, n = 3, target = 3

Output: -1

Explanation: Houses are already painted with a total of 4 neighborhoods [{3},{1},{2},{3}] different of target = 3.

Constraints:

• m == houses.length == cost.length
• n == cost[i].length
• 1 <= m <= 100
• 1 <= n <= 20
• 1 <= target <= m
• 0 <= houses[i] <= n
• 1 <= cost[i][j] <= 104

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	minCost(int[] houses, int[][] cost, int nColors, int tGroups)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

minCost

public int minCost(int[] houses,
                   int[][] cost,
                   int nColors,
                   int tGroups)