Different orientation on this triangle

AI Thread Summary
To achieve the desired output of a descending triangle of asterisks, the current code needs modifications. The original code generates an ascending triangle by incrementing the number of asterisks printed in each line. To correct this, the loop should be adjusted to count down from the total number of lines to zero. Specifically, the outer loop should iterate from the total number of lines down to zero, and the inner loop should print the corresponding number of asterisks based on the current line number. It is also important to ensure that the loop conditions are correctly set to avoid infinite loops, which can occur if the loop variables are not managed properly. Implementing a function to handle the printing of asterisks could further streamline the code and enhance readability.
Demon117
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I am trying to get a different orientation on this triangle; specifically I want this output:

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

Here is the code that I have

Code:
#include <iostream>
using namespace std;

int main () 
{
	int lines=10;
	int start = 0;
	int dots;
	while (start < lines) {
		// We start at 0, then gradually increment
		for (dots = 0; dots <= start; dots++)
			cout << "*";
		cout << endl;
		start++;// Increment
	}
    system("pause");
	return 0;
}

and it generates this output:

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

What do I need to change?
 
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Have the for loop count down instead of up?
 


DavidSnider said:
Have the for loop count down instead of up?

Nope, this has been tried already and it produces an infinite loop.
 


matumich26 said:
Nope, this has been tried already and it produces an infinite loop.

Then I think you went wrong somewhere. Can you post code again?
 


matumich26 said:
Nope, this has been tried already and it produces an infinite loop.
If it goes into an infinite loop, you're doing it wrong.

There's two ways to do it that I can think of. Either count through the while loop as you do now, and work out how many asterisks you want. Or count the other way in your while loop. I'd do the former, probably.

Assuming you're printing, say, 7 lines. You start out and the counter is 0. How many asterisks to print? 7 right? Next line, counter is 1. So you print 7-1=6 asterisks. In general, it's (lines - counter) right?
 


for extra credit you might want to build a function like:

void printStars(int numStars) {
...
}

then in main:
for(int i=0;i<lines;i++) {
printStars(lines - i);
}
 


DavidSnider said:
Then I think you went wrong somewhere. Can you post code again?

Here:

Code:
#include <iostream>
using namespace std;

int main () 
{
	int lines=10;
	int start = 0;
	int dots;
	while (start < lines) {
		// We start at 0, then gradually increment
		for (dots = 0; dots <= start; dots++)
			cout << "*";
		cout << endl;
		start++;// Increment
	}
    system("pause");
	return 0;
}
 


I meant post the code where you counted down and got the infinite loop problem :smile:

But I'd try the method I suggested earlier with an external function to print each line first.

matumich26 said:
Here:

Code:
#include <iostream>
using namespace std;

int main () 
{
	int lines=10;
	int start = 0;
	int dots;
	while (start < lines) {
		// We start at 0, then gradually increment
		for (dots = 0; dots <= start; dots++)
			cout << "*";
		cout << endl;
		start++;// Increment
	}
    system("pause");
	return 0;
}
 


Like other people have said change the loop.

When you change the loop to go from sup(Set) to inf(Set) you also need to change the comparisons you make from less than to greater than.

Also make sure you are using signed numbers. You can get in an infinite loop if you use these incorrectly.
 

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