CF389B.Fox and Cross

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

Fox Ciel has a board with $n$ rows and $n$ columns. So, the board consists of $n×n$ cells. Each cell contains either a symbol '.', or a symbol '#'.

A cross on the board is a connected set of exactly five cells of the board that looks like a cross. The picture below shows how it looks.

Ciel wants to draw several (may be zero) crosses on the board. Each cross must cover exactly five cells with symbols '#', and any cell with symbol '#' must belong to some cross. No two crosses can share a cell.

Please, tell Ciel if she can draw the crosses in the described way.

输入格式

The first line contains an integer $n$ ( $3<=n<=100$ ) — the size of the board.

Each of the next $n$ lines describes one row of the board. The $i$ -th line describes the $i$ -th row of the board and consists of $n$ characters. Each character is either a symbol '.', or a symbol '#'.

输出格式

Output a single line with "YES" if Ciel can draw the crosses in the described way. Otherwise output a single line with "NO".

输入输出样例

输入#1
```
5
.#...
####.
.####
...#.
.....
```
输出#1
```
YES
```
输入#2
```
4
####
####
####
####
```
输出#2
```
NO
```

输入#3

6
.#....
####..
.####.
.#.##.
######
.#..#.

输出#3

YES

输入#4

6
.#..#.
######
.####.
.####.
######
.#..#.

输出#4

NO

输入#5
```
3
...
...
...
```
输出#5
```
YES
```

说明/提示

In example 1, you can draw two crosses. The picture below shows what they look like.

In example 2, the board contains 16 cells with '#', but each cross contains 5. Since 16 is not a multiple of 5, so it's impossible to cover all.

首页