图形问题

A - 1 CodeForces - 510A
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
#########
…#
#########
#…
#########
…#
#########
#…
#########
题目大意：通过代码打出相应的图形；这次是要比较简单的蛇。
代码如下（已AC）：

#include<iostream>
using namespace std;
int main()
{
	int n, m;
	cin >> n >> m;
	for (int i = 1; i <= n; i++)
	{
		if (i % 2 == 1)
		{
			for (int j = 0; j < m; j++)
				cout << "#";
			cout << endl;
		}//行数为单数就全输出“#”
		else if((i/2)%2==0)//双数行中的双数；
		{
			cout << "#";
			for (int j = 1; j < m; j++)
				cout << ".";
			cout << endl;
		}
		else单数行中的单数；
		{
			for (int j = 1; j < m; j++)
				cout << ".";
			cout << "#" << endl;
		}
	}
	return 0;
}