左旋方阵

#include <stdio.h>

int main()
{
	static int a[20][20], i, j, k = 1, n;

	scanf("%d", &n);
	for (i = 0; i < (n + 1) / 2; i++)
	{
		for (j = i; j < n - i; j++)
		{//right
			a[i][j] = k++;
		}
		for (j = i + 1; j < n - i; j++)
		{//left
			a[j][n - i - 1] = k++;	
		}
		for (j = n - i - 2; j >= i; j--)
		{//down 
			a[n - i - 1][j] = k++;
		}
		for (j = n - i - 2; j > i; j--)
		{//up
			a[j][i] = k++;
		}			
	}
	for (i = 0; i < n; i++)
	{
		for (j = 0; j < n; j++)
		{
			printf("%2d\t", a[i][j]);
		}
		if(i != n - 1){
			printf("\n");
		}	
	}
	return 0;
}