#BC133回型矩阵

//回型矩阵
#include<stdio.h>
int main()
{
  int arr[20][20], n;
  printf("请输入n的值：\n");
  scanf_s("%d", &n);
  int up = 0, left = 0, right = n - 1, down = n - 1;
  int x = 1;
  while (x <= n * n)
  {
    for (int i = left; i <= right; i++)
    {
      arr[up][i] = x++;
    }
    up++;
    for (int i = up; i <= down; i++)
    {
      arr[i][right] = x++;
    }
    right--;
    for (int i = right; i >= left; i--)
    {
      arr[down][i] = x++;
    }
    down--;
    for (int i = down; i >= up; i--)
    {
      arr[i][left] = x++;
    }
    left++;
  }
  //遍历
  for (int i = 0; i < n; i++)
  {
    for (int j = 0; j < n; j++)
    {
      printf("%d\t", arr[i][j]);
    }
    printf("\n");
  }
  return 0;
}