学步园

Description

   A   B   C   D   E   F   G   H

   V   W   X   Y   Z   A   B   I

   U   J   K   L   M   N   C   J

   T   I   H   G   F   E   D   K

   S   R   Q   P   O   N   M   L

Input

Output

Sample Input

4 9

Sample Output

   A   B   C   D   E   F   G   H   I
   V   W   X   Y   Z   A   B   C   J
   U   J   I   H   G   F   E   D   K
   T   S   R   Q   P   O   N   M   L

#include<iostream>

using namespace std;

int main()
{
	int r,co,time = 1;
	char c = 'A';
	cin >> r >> co;
	
	//由于m,n没给定范围，所以声明动态数组
	char **arr = new char*[r];   
    for(int i = 0;i <= r;++i)   
      arr[i] = new char[co];   
	for(int i = 0;i <= r;++i)
		for(int j = 0;j <= co;++j)
			arr[i][j] = 0;
	
	arr[1][1] = 'A';
	int x = 1,y = 1;
	while(time < r * co)//用次数来控制最方便
	{
		while(y+1 <= co && !arr[x][y+1])//注意“预判”，很重要 y+1 <= co 和 y <= co-1是不一样的性质
		{
			if(c >= 90)	c -= 26;
			arr[x][++y] = ++c;
			++time;
		}
		while(x+1 <= r && !arr[x+1][y])
		{
			if(c >= 90)	c -= 26;
			arr[++x][y] = ++c;
			++time;
		}
		while(y-1 >= 1 && !arr[x][y-1])
		{
			if(c >= 90)	c -= 26;
			arr[x][--y] = ++c;
			++time;
		}
		while(x-1>= 1 && !arr[x-1][y])
		{
			if(c >= 90)	c -= 26;
			arr[--x][y] = ++c;
			++time;
		}
	}
	for(int i = 1;i <= r;++i)
	{
		for(int j = 1;j <= co; ++j)
			cout << "   " << arr[i][j];
		cout << endl;
	}
	return 0;
}