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
#########
........#
#########
#........
#########
........#
#########
#........
#########
解题思路：按照题意输出，奇数层全部输出’#’，剩下的偶数层分两种情况，4的倍数则先输出’#‘再输出’.’，2的倍数则反之。
//miku saiko
#include<iostream>
using namespace std;
int main()
{
int n, m, i, j;
cin >> n >> m;
for (i = 1; i <= n; i++)
{
if (i % 2)
{
for (j = 1; j <= m; j++)
cout << '#';
cout << endl;
}
else
if (i % 4==0)
{
cout << '#';
for (j = 2; j <= m; j++)
{
cout << '.';
}
cout << endl;
}
else
{
for (j = 1; j < m; j++)
{
cout << '.';
}
cout << '#' << endl;
}
}
return 0;
}