HourGlass Star Pattern program in C - c

Question

I had an interview in which I was asked to write an hourglass star pattern program. For example, if the user specifies 5 then the pattern must be like:
*****
***
*
***
*****
If 7 then the pattern must be like:
*******
*****
***
*
***
*****
*******
My coding for the pattern is:
for(i=n; i>=1; i--)
{
for(j=i; j<n; j++)
{
printf(" ");
}
for(j=1; j<=(2*i-1); j++)
{
printf("*");
}
printf("\n");
}
for(i=1; i<=n; i++)
{
for(j=i; j<n; j++)
{
printf(" ");
}
for(j=1; j<=(2*i-1); j++)
{
printf("*");
}
printf("\n");
}
Please help me to solve this problem.

Answer 1

You can use only 1 loop for printing:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char* argv[])
{
int a=0;
scanf("%d",&a);
int i=0;
char* asterisk=malloc(sizeof(char)*a);
memset(asterisk,'*',a*sizeof(char));
while(i<a)
{
if(i<=a/2)
printf("%*.*s\n",a-i,a-2*i,asterisk);
else
printf("%*.*s\n",i+1,2*(i+1)-a,asterisk);
i++;
}
free(asterisk);
return 0;
}

Answer 2

This could help. It's not the best that there is and it could be made more efficient, but it should give you an idea.
#include<stdio.h>
void print(int space, int star)
{
while (space--) {
printf(" ");
}
while (star--) {
printf("*");
}
printf("\n");
}
void main()
{
int star,space,i,j;
printf("Enter number:");
scanf("%d",&star);
j=star/2;
i=star;space=0;
while (space<j || star>0) {
print(space,star);
space=space+1;star=star-2;
}
space=j-1;star=3;
while(space>0 || star<=i) {
print(space,star);
space=space-1;star=star+2;
}
}
Please comment if you have any doubts.
Note:The above code is just a sample. There are many (and far more efficient) ways to implement the pattern and it is encouraged to find a way to do so.
Edit:The code now prints only 1 star in the middle. Did not notice that. Apologies.

Answer 3

Guys I found the mistake, What i did in that code.
#include <stdio.h>
void main()
{
int i, j, n;
printf("Enter Odd value for n : ");
scanf("%d", &n);
for(i=n/2+1; i>1; i--)
{
for(j=i; j<n; j++)
{
printf(" ");
}
for(j=1; j<=(2*i-1); j++)
{
printf("*");
}
printf("\n");
}
for(i=1; i<=n/2+1; i++)
{
for(j=i; j<n; j++)
{
printf(" ");
}
for(j=1;j<=(2*i-1); j++)
{
printf("*");
}
printf("\n");
}
}
Thank You!!!!!!! Guys for your help.