Thread: Program to make stars mostly done, need help?

Ok, I am new to this board so if I have gone out of line or done something by accident, I will apologize in advance. I want to make a program that generates a number of lines with stars. Only Odd numbers though. The user is asked to input a number and the output places that many lines in out of stars. EX>.

Input number: 5;

*

***

*****

***

*

It doesn't put the line 2 with 2 stars and line 4 with 4 stars. Number being inputted is number of stars on middle line. Eg. 7 would have 7 stars.

So far this is what I have...

Code:

#include <stdio.h>

int main (void)

{

int num, space, spaces, line;

printf("Please enter an Odd number of lines in the diagram: ");
scanf("%d", &num);

if((num <= 0)||(num%2 == 0))
printf("\nPlease input a positive Odd Integer");

else{

space = num;

for (int i=1; i<=num-2; i++)
        {

        for (int j=1; j<=space; j++)
        printf(" ");

        for (int j=1; j<=2*i-1; j++)
        printf("*");
        printf("\n");
        space--;
        }
       }
return 0;
}

Thank you in advance for reading this post.

Originally Posted by patso

Ok, I am new to this board so if I have gone out of line or done something by accident, I will apologize in advance. I want to make a program that generates a number of lines with stars. Only Odd numbers though. The user is asked to input a number and the output places that many lines in out of stars. EX>.

Input number: 5;

*

***

*****

***

*

It doesn't put the line 2 with 2 stars and line 4 with 4 stars. Number being inputted is number of stars on middle line. Eg. 7 would have 7 stars.

So far this is what I have...

Code:

#include <stdio.h>

int main (void)

{

int num, space, spaces, line;

printf("Please enter an Odd number of lines in the diagram: ");
scanf("%d", &num);

if((num <= 0)||(num%2 == 0))
printf("\nPlease input a positive Odd Integer");

else{

space = num;   //??????????????????????

How about a nice do while loop for this? 

do   {
   printf("Please enter an Odd positive number...");
   scanf("%d", &num);

   garbage = getchar();  //get's rid of the '\n' in the input stream.
}while(num < 1 || num %2 == 0);



for (int i=1; i<=num-2; i++)
        {

        for (int j=1; j<=space; j++)
        printf(" ");

        for (int j=1; j<=2*i-1; j++)
        printf("*");
        printf("\n");
        space--;
        }
       }
return 0;
}

Thank you in advance for reading this post.

Are you compiling this in C? Looks like C++.

So what's your output look like?

using SSH to compile, it is in school so I am pretty sure it is C. I use pico at school.

My output shows

input number: 5;

*

***

*****

But as soon as I go past 5 it gets to be a large number of stars for 7 or 9. I also don't know how to get it to go from the 5 stars to the 3 to the 1.

*****

***

*

The below code puts out what you need, but I suck at C and for loops give me a headache, but you should be able to rewrite it to whatever is required. Not formatted either -

Input #7 outputs;
*
***
*****
*******
*****
***
*

Code:

else{

for (int i=0; i<=num; i++)
  {

      if(i%2==0){
         int k=0;
         
        while(k<=i){
          printf("*");
          k++;
         }
        }
         if(i<num){
           printf("\n");
           }
         }
         
for (int l=num-2; l>=0; l--)
   {

      if(l%2==0){
         int k=0;
         
        while(k<=l){ 
          printf("*");
          k++;
         }
        }
           if(l<=num){
             printf("\n");
            }
           }     
          }

Awesome, thank you so much. You were extremely helpful. This is exactly what I needed, and it is easy and clear so I can read it. Oldman47 you were an excellent help.