蛇形填数

/******************************
作者：cncoderalex
博客：http://blog.youkuaiyun.com/cncoderalex
*******************************/

#include <iostream>  
#include <memory>  
#include <string>  
#include <algorithm>  

using namespace std;

#define MAXN 20  

int Ary[MAXN][MAXN];

void FillSnakeSquare(int n)
{
	int total = 1;
	int x = 0, y = n - 1;

	memset(Ary, 0, sizeof(Ary));
	Ary[x][y] = 1;
	while (total < n * n)
	{
		while (x < n - 1 && !Ary[x + 1][y]) Ary[++x][y] = ++total;
		while (y > 0 && !Ary[x][y - 1]) Ary[x][--y] = ++total;
		while (x > 0 && !Ary[x - 1][y]) Ary[--x][y] = ++total;
		while (y < n - 1 && !Ary[x][y + 1]) Ary[x][++y] = ++total;
	}
}

void PrintAry(int n)
{
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < n; j++)
		{
			printf("%3d", Ary[i][j]);
		}

		printf("\n");
	}
}

int main()
{
	printf("http://blog.youkuaiyun.com/cncoderalex");
	printf("\n");

	int n;
	while (scanf("%d", &n) != EOF)
	{
		FillSnakeSquare(n);
		PrintAry(n);
	}

	system("pause");

	return 0;
}