CF1198D.Rectangle Painting 1

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

There is a square grid of size n×nn \times n . Some cells are colored in black, all others are colored in white. In one operation you can select some rectangle and color all its cells in white. It costs max(h,w)\max(h, w) to color a rectangle of size h×wh \times w . You are to make all cells white for minimum total cost.

输入格式

The first line contains a single integer nn ( 1n501 \leq n \leq 50 ) — the size of the square grid.

Each of the next nn lines contains a string of length nn , consisting of characters '.' and '#'. The jj -th character of the ii -th line is '#' if the cell with coordinates (i,j)(i, j) is black, otherwise it is white.

输出格式

Print a single integer — the minimum total cost to paint all cells in white.

输入输出样例

  • 输入#1

    3
    ###
    #.#
    ###
    

    输出#1

    3
    
  • 输入#2

    3
    ...
    ...
    ...
    

    输出#2

    0
    
  • 输入#3

    4
    #...
    ....
    ....
    #...
    

    输出#3

    2
    
  • 输入#4

    5
    #...#
    .#.#.
    .....
    .#...
    #....
    

    输出#4

    5
    

说明/提示

The examples and some of optimal solutions are shown on the pictures below.

首页