Thread: Help writing a program

You'll need a loop. Do you know how to code a "for" loop?

Loops would work something like this.

Code:

...
int i = 0;
int j = 0;
for(i = 0; i < height; i++) {
    for(j = 0; j < width; j++) {
        printf("*");
    }
    printf("\n");
}
...

Something along those lines should work.

Well the number will tell your loop how many times to loop. Then inside the loop you can print your "*". This will print the "*" every iteration.

So when you get the users input, and you get the width, you lloop width amount of times and print "*".

putc(' '); will print a space character
putc('*') - star cgharacter - you should mix them for the 2nd and futher lines

Here's a basic "for" loop. I'll write it, then I'll explain it.

Code:

int i ; 

for ( i = 0 ; i < width ; i++ ) 
{
    do-one-thing... ; 
}

some-next-instruction ;

The code in RED is required for every "for" loop. (There is a shortcut to leave off the curly braces, but I won't get into that).

The "for" says to loop some number of times. The parens enclose the INITIALIZER, the CONDITION and the INCREMENT, in that order.

To start the loop, you set up an initializer. It is typical in a loop to control it with an INT. Here, variable i is the int. We set it with an initial values of 0. This is the most common thing to do.

The flow of execution is this:
1) the initializer is performed (this is only done once)
2) the condition is checked
3) if the condition is TRUE, then the code between the braces is executed. If the condition if false, then the loop is done, and control passes to the next instruction after the last curly brace.
4) If the code between the braces was executed because the condition was true, then the increment is performed. The process repeats again, starting with step 2 above.

So, let's take a simple example. Let's say you wanted to do the same thing (like print a '*') 5 times. You would initialize i to 0, you would set a condition for i to be less than 5 (because counting from 0 to 4 is "5 times"), and you would set an increment to bump i by one each loop.

Does that make sense?

This is just the very basics, but should be enough to get you going in the right direction.

Todd

EDIT - if not, hopefully the other posters who posted will have helped - who posted while I was writing this!! Man, you guys are fast!

You should validate the width prior to entering the loop.

Ok thank you. Now I just have to work on where to put the printf(" "); at.

Thanks

Code:

     6  #include <stdio.h>
     7
     8  int main(void)
     9
    10  {
    11
    12  int height, width;
    13  int i = 0;
    14  int j = 0;
    15
    16  printf("Enter width:");
    17  scanf("&#37;d", &width);
    18  printf("Enter height:");
    19  scanf("%d", &height);
    20
    21  for (i = 0; i < height; i++) {
    22          for(j = 0; j < width; j++) {
    23                  printf("*");
    24          }
    25          printf("\n");
    26  }
    27
    28  printf("PROGRAM ENDS\n");
    29  return 0;
    30
    31  }

When you print the *, compare j and width to see where you are.

If i is 0, don't worry about the check, after that, if j is equal to 0 or j is equal to width you can print *, else you can print ' '.

Make a flowchart, translate your code into the flowchart, insert appropriate spaces into flowchart, translate into code.