Record 1 --- digital phalanx rotation

 

#include<stdio.h>
#include<string.h>
int main()
{
    int i,j=0,n,k,a[20][20],num=1;scanf("%d",&n);
 for(k=0;k<n/2;k++)
 {
    for(i=k;i<n-1-k;i++)
          a[i][k]=num++;
    for(i=k;i<n-1-k;i++)
        a[n-1-k][i]=num++;
    for(i=n-1-k;i>k;i--)
        a[i][n-1-k]=num++;
    for(i=n-1-k;i>k;i--)
        a[k][i]=num++;
 }
 if(n%2==1)
     A [n- / 2 ] [n-/ 2 ] * = n- n-; when // n is odd, there will be little above code bug, correction
  int In Flag = 0 ;
  for (I = 0 ; I <n-; I ++ )
      for (J = 0 ; J <n-; J ++ )
     {
       flag++;
       printf("%4d",a[i][j]);
       if(flag%n==0)
           the printf ( " \ n- " ); // control line feed
     }
return 0;
}