Thread: Basic C Homework Question - likely easy for you but sending me for a loop

Reading through the board I've found people prefer verbatim what the professor is looking for. I'm not looking for someone to answer this for me just point me towards the right direction as I'm at a loss as to where to start with the code.

"your program will draw the following figure on the screen using a combination of spaces and asterisks" (_ = space)

_*****
__*****
___*****
____*****
_____*****
_____*****
_____*****
_____*****
____*****
___*****
__*****
_*****
_*****
_*****
_*****
__*****
___*****
____*****

2. you will use the definition of function main shown below (do not change this function)

Code:

int main (void) {
   int i = 0;
   while (i < 41) {
      print_line (sin(i/(3.1416*2))*20+21,5);
      i = i + i;
   }
   return 0;
}

------
my question is so far I know I need to create another function called "print_line" but I'm simply lost as to how to proceed.. I've searched through the forums and around the net for something similar to get ideas however I've been unable to find something. I'm not looking for anyone to do my work for me I need to / want to complete this myself I just don't know how to start. Thanks for any help.

solid, yea I notice I did mess that up when typing to the page however in the program it is correct. I'll start down that path and see if I can make some sense of it. do you think I'll need to create a print_line function end it and then create another like mymain in order to call the print_line and main functions into play or should I be able to do all the additional coding within print_line?
thank you for the help and advice

You should be able to do everything in the "print_line()" function - i.e. the only functions your program should contain are the given "main()" and "print_line()".

Just trying to lay the code down and start seeing the mistakes along the way and the first thing I'm getting in the compiler is "

Code:

$ gcc -ansi -std=c99 -pedantic -ggdb -lm program5.c
program5.c: In function ‘main’:
program5.c:24:8: error: too many arguments to function ‘print_line’
        print_line (sin(i/(3.1416*2))*20+21,5);
        ^
program5.c:7:5: note: declared here
 int print_line(int i) {
     ^
"

Code:

# include <stdio.h>
# include <math.h>




int print_line(int k) {
   k = 0;
   while (k < 41) {
      printf(" ");
      k = k + 1;
   }
   printf("****\n");


   return 0;
}








int main (void) {
    int i = 0;
    while (i < 41) {
       print_line (sin(i/(3.1416*2))*20+21,5);
       i = i + 1;
    }
    return 0;
}

sooooo... I'm confused in what way it's telling me I'm dumb

I misspoke, by use the function to alter the spaces I meant point to the function and have function main set the spaces for me, not edit function main. However thank you for the clarity and caution. Originally I set 41 to frame the code structure but now it needs to become dynamic, I'll work on my functions and work with K as you suggested, your help is appreciated.

Code:

# include <stdio.h>
# include <math.h>




int print_line(int spaces, int five) {
   while (spaces > 0) {
      printf(" ");
      spaces = spaces - 1;
   }
   printf("****\n");
   return 0;
}


int main (void) {
    int i = 0;
    while (i < 41) {
       print_line (sin(i/(3.1416*2))*20+21,5);
       i = i + 1;
    }
    return 0;
}

should do it. What is the point of the "5" in the second argument of the print_line in the main function? It looks like that would give some sort of constant but I don't see it being implemented anywhere? Maybe a constant minimum of 5 spaces? Seems unnecessary.

Originally Posted by laserlight

I have told you twice that I think the second argument is the number of asterisks to print per line. The only way to be sure is to ask your professor.

I'm very new to C and didn't fully understand the roles each argument had in the end result. Now that I've pieced it apart and understand it better your observation makes sense. I e-mailed the professor asking him for clarification on the # of asterisks he would like between 5 or 4 (5 in his image, 5 in the argument, 4 in the instructions) which should clear some things up. For now I will write the program to use that second argument as the # of asterisks. Thanks!

Originally Posted by WoodSTokk

Your while-loop iterate allways to 41, but this should be variable (the value from the function argument).

Hint: you can see what the function receive as argument with:

Code:

int print_line (int l, int m) {
    printf("-> l=%d / m=%d\n", l, m);
    return 0;
}

Thank you for the help yes that was my original code that was worse than my current not very good code. I have since changed it to

Code:

while (spaces > 0)

thanks for the code to use to see what the function receives as an argument, I'll play with that to help learn. Take care!!