CodeForces - 510A（水题）

Fox Ciel starts to learn programming. The first task is drawing a fox! However, that turns out to be too hard for a beginner, so she decides to draw a snake instead.

A snake is a pattern on a n by m table. Denote c-th cell of r-th row as (r, c). The tail of the snake is located at (1, 1), then it’s body extends to (1, m), then goes down 2 rows to (3, m), then goes left to (3, 1) and so on.

Your task is to draw this snake for Fox Ciel: the empty cells should be represented as dot characters (’.’) and the snake cells should be filled with number signs (’#’).

Consider sample tests in order to understand the snake pattern.

Input
The only line contains two integers: n and m (3 ≤ n, m ≤ 50).

n is an odd number.

Output
Output n lines. Each line should contain a string consisting of m characters. Do not output spaces.

Examples
Input
3 3
Output

…#

Input
3 4
Output

…#

Input
5 3
Output

…#

#…

Input
9 9
Output
#########
…#
#########
#…
#########
…#
#########
#…
#########

题意就是奇数行全是“#”，4的倍数行开头是“#”，其他结尾是“#”，其他为“.”。简单分类一下就好
ac代码

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <math.h>
#include <cstdlib>
#include <queue>
#include<iomanip>
using namespace std;
int main()
{
	int n,m;
	while (cin >> n >> m)
	{
		for (int i = 1; i <= n; i++)
		{		for (int j = 1; j <= m; j++)
			{
			if (i % 2)
				printf("#");
			else if (i % 4) {
				if (j == m)printf("#");
				else printf(".");
			}
			else {
				if (j == 1) printf("#");
				else printf(".");
			}
		}printf("\n");
	}
		}
	
	
}