用C语言打印空心菱形（要求for循环）

题目错了吧，如果你输入偶数就不会有◇啊，只有这个题目
由键盘输入正数n，要求输出2*n+1行的菱形图案，要求菱形左边紧靠屏幕左边
#include "stdio.h"
main()
{ int i,j;
int n;

scanf("%d",&n);
for(i=0;i<=n+1;i++)
{ for(j=n-i;j>=0;j--)
printf(" ");
for(j=0;j printf("* ");
printf("\n"); }
for(i=0;i { for(j=0;j printf(" ");
for(j=n-i;j>0;j--)
printf("* ");
printf("\n"); }
getch();
}

---------------------------------
# include
# include
void main()
{
int i,j,a,b,n;
printf("please enter size");
scanf("%d",&n);
for(i=1;i {
for(j=1;j<=n+i-1;j++)
if(j==n-i+1 ||j==n+i-1)
printf("*");
else
printf(" ");
printf("\n");
}
for(i=1;i<=2*n-1;i++)
printf("*");
printf("\n");
for(a=1;a {
for(b=1;b<=2*n-a-1;b++)
if(b==n-(n-a-1)||b==2*n-a-1)
printf("*");
else
printf(" ");
printf("\n");}
}
--------------------------------------------------
结果
please enter size 15
------------------------------
*
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
*****************************
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
*
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