Thread: Printing Patterns Using Recursion

Hi guys,

I'm trying to print patterns such as the following:

****
***
**
*
**
***
****

using recursion. I can figure out the code for the top half and the bottom half seperately. i.e i can print

****
***
**
*

and

*
**
***
****

each recursively. I'm trying to combine these into one function. How could I call the functions so that I could combine the two?

here are my functions

Code:

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


void printTriangle (int n)
{
 if (n==1)
 {printf("*");
  printf("\n");
 }
 
 else if(n>1)
 {   int i;
     for (i=0;i<n;i++)
     printf("*");
     printf("\n");
     printTriangle(n-1);
 }
}

void printInvertedTriangle(int n)
{
    if (n==1)
 {printf("*");
  printf("\n");
 }
 
 else if(n>1)
 {

     printInvertedTriangle(n-1);
     int i;
     for (i=0;i<n;i++)
     printf("*");
     printf("\n");
 }
}



int main(void)
{printInvertedTriangle(4);
}

I know, I was going through some exercises at the back of a book I have. Most of them are easily solvable using loops. I was thinking this exercise was trying to show a way of doing recursion that I don't know how to do, or something like that.