*_full_triangle_hollow.c

#include <stdio.h>
#include <stdlib.h>

/*

n=5 will print

     *
    * *
   *   *
  *     *
 *********
 
*/

int main()
{
    int i,j,k,n;
    printf("Enter the number of rows : ");
    scanf("%d",&n);

    printf("\n");
    for (i=1;i<=n;i++)
    {
        for (j=1;j<=(n-i);j++)
        {
            printf(" ");
        }
        for (k=1;k<=2*i-1;k++)
            if(k==1||k==2*i-1||i==n)
        {
            printf("*");
        }
        else
        {
            printf(" ");
        }
        printf("\n");
    }
    return 0;
}