#include<stdio.h> 
int n;
void draw(int n)
{
int i,j;
for (i=1-(n>>1);i<=n;i++) 
if (i>=0) 
{ 
for (j=0;j<i;j++) printf("  "); 
for (j=1;j<=2*(n-i)+1;j++) printf(" *"); 
printf("\n"); 
} 
else 
{ 
for (j=i;j<0;j++) printf("  "); 
for (j=1;j<=n+2*i+1;j++) printf(" *"); 
for (j=1;j<=-1-2*i;j++) printf("  "); 
for (j=1;j<=n+2*i+1;j++) printf(" *"); 
printf("\n"); 
}
}
int main() 
{ 
printf("请设置尺寸(n>=4):"); 
scanf("%d",&n); 
draw(n);
return 0; 
}