CodeForces - 1059B

time limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputStudent Andrey has been skipping physical education lessons for the whole term, and now he must somehow get a passing grade on this subject. Obviously, it is impossible to do this by legal means, but Andrey doesn’t give up. Having obtained an empty certificate from a local hospital, he is going to use his knowledge of local doctor’s handwriting to make a counterfeit certificate of illness. However, after writing most of the certificate, Andrey suddenly discovered that doctor’s signature is impossible to forge. Or is it?For simplicity, the signature is represented as an n×m grid, where every cell is either filled with ink or empty. Andrey’s pen can fill a 3×3 square without its central cell if it is completely contained inside the grid, as shown below.
xxx
x.x
xxx
Determine whether is it possible to forge the signature on an empty n×m grid.InputThe first line of input contains two integers n and m(3≤n,m≤10003≤n,m≤1000).Then n lines follow, each contains m characters. Each of the characters is either ‘.’, representing an empty cell, or ‘#’, representing an ink filled cell.OutputIf Andrey can forge the signature, output “YES”. Otherwise output “NO”.You can print each letter in any case (upper or lower).
Examples
Input
3 3
###
#.#
###
Output
YES
Input
3 3
###
###
###
Output
NO
Input
4 3
###
###
###
###
Output
YES
Input
5 7
…….
.#####.
.#.#.#.
.#####.
…….
Output
YES
Note:In the first sample Andrey can paint the border of the square with the center in (2,2).In the second sample the signature is impossible to forge.In the third sample Andrey can paint the borders of the squares with the centers in (2,2) and (3,2): we have a clear paper:
…
…
…
…
use the pen with center at (2,2).
###
#.#
###
…
use the pen with center at (3,2).
###
###
###
###
In the fourth sample Andrey can paint the borders of the squares with the centers in (3,3) and (3,5).

暴力枚举每个点，如果这个点周围八个带你都是#，就涂，否则不涂。R代表涂过了。最后在判断有没有未涂过的#即可。

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#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
string Map[1020];
void Process(int x, int y)	{
	int Size = 0;
	for (int i = -1; i <= 1; i++){
		for (int j = -1; j <= 1; j++){
			if (i == 0 && j == 0) {
				continue;
			}
			if (Map[x + i][y + j] == '#' || Map[x + i][y + j] == 'R') {
				++Size;
			}
		}
	}
	if (Size == 8)	{
		for (int i = -1; i <= 1; i++){
			for (int j = -1; j <= 1; j++){
				if (i == 0 && j == 0) {
					continue;
				}
				Map[x + i][y + j] = 'R';
			}
		}
	}
}
int main() {
	int n, m;
	bool flag = false;
	string s;
	cin >> n >> m;
	for (int i = 1; i <= n; i++){
		cin >> Map[i];
		Map[i] = ' ' + Map[i];
	}
	for (int i = 2; i < n; i++) {
		for (int j = 2; j < m; j++) {
			Process(i, j);
		}
	}
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			if (Map[i][j] == '#') {
				flag = true;
			}
		}
		if (flag) {
			break;
		}
	}
	puts(flag ? "No" : "Yes");
	return 0;
}