#include <stdio.h>
#include <string.h>
#define maxn 20
int a[maxn][maxn];
int main()
{
int n, x, y, tot = 0;
scanf("%d", &n);
memset(a, 0, sizeof(a));
tot = a[x = 0][y = n - 1] = 1;
while(tot < n * n)
{
while(x + 1 < n && !a[x+1][y]) a[++x][y] = ++tot;
while(y - 1 >= 0 && !a[x][y-1]) a[x][--y] = ++tot;
while(x - 1 >= 0 && !a[x-1][y]) a[--x][y] = ++tot;
while(y + 1 < n && !a[x][y+1]) a[x][++y] = ++tot;
}
for(x = 0; x < n; x++)
{
for(y = 0; y < n; y++)
{
printf("%3d",a[x][y]);
}
printf("\n");
}
return 0;
}
输出效果如下: