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Oct 6th, 2005

Help w/ for loop.

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I'm trying to put together this program that creates a for loop but my end result is not positioned the way I need it like this but flipped around so it looks like a christmas tree effect.

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

Please help I'm still learning and I can't figure it out for the life of me!

Source code:

C++ Syntax (Toggle Plain Text)
#include <iostream>
 
using namespace std;
 
int main()
{
	int i, j, lines;
 
    cout << "This Program creates Christmas Trees." << endl;
 
	do
	{
		cout << "Please enter a number between 1 and 30" << endl;
		cin  >> lines; 
	}while (lines < 1 || lines > 30);
 
	for(j=1; j<=lines; j++)
	{
 
	   for(i=1; i<=40; i=i++)
	   {
	      cout << " ";
	   }
 
	   for(i=1; i<=j; i=i++)
	   {
		  cout << "*";
	   }
	   cout << endl;
	}
}
#include <iostream>

using namespace std;

int main()
{
	int i, j, lines;

    cout << "This Program creates Christmas Trees." << endl;

	do
	{
		cout << "Please enter a number between 1 and 30" << endl;
		cin  >> lines; 
	}while (lines < 1 || lines > 30);

	for(j=1; j<=lines; j++)
	{

	   for(i=1; i<=40; i=i++)
	   {
	      cout << " ";
	   }
	   
	   for(i=1; i<=j; i=i++)
	   {
		  cout << "*";
	   }
	   cout << endl;
	}
}

<< moderator edit: added code tags: [code][/code] >>

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smallville

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Oct 6th, 2005

Re: Help w/ for loop.

In your for loops

change

C++ Syntax (Toggle Plain Text)

i=i++  
to 
i++

code will work fine

SpS

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Oct 6th, 2005

Re: Help w/ for loop.

C++ Syntax (Toggle Plain Text)
#include <iostream>
 
using namespace std;
 
int main()
{
  int i, j, lines;
 
  cout << "This Program creates Christmas Trees." << endl;
 
  do
    {
      cout << "Please enter a number between 1 and 30" << endl;
      cin  >> lines;
    }while (lines < 1 || lines > 30);
 
  for(j=0; j<lines; j++)
    {
      for(i=0; i<=j; i++)
        {
          cout << "*";
        }
      cout << endl;
    }
}
#include <iostream>

using namespace std;

int main()
{
  int i, j, lines;

  cout << "This Program creates Christmas Trees." << endl;

  do
    {
      cout << "Please enter a number between 1 and 30" << endl;
      cin  >> lines;
    }while (lines < 1 || lines > 30);

  for(j=0; j<lines; j++)
    {
      for(i=0; i<=j; i++)
        {
          cout << "*";
        }
      cout << endl;
    }
}

You were really close.

Just take out the first for loop, and the i=i++ is something you *do not* want to do (think about it).

-Fredric

Daishi

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Oct 6th, 2005

Re: Help w/ for loop.

thanks, it works but it's showing like in the post... however I need it to look more like an equal triangle from the top down

**********

the reason the other one was there is to bring it to the center of the program. The extra spaces it what brought it to the middle.. I'm completely stuck.

smallville

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Oct 7th, 2005

Re: Help w/ for loop.

Err', sorry, reread your post more carefully..if you want a christmas tree effect, then you need to include that for loop I said to leave out, but set the initial value of i to j in it, change 40 to lines, and increment i correctly. Then you have to make one little change to the second for loop and you should get a Christmas tree. Ok, no more hints!

-Fredric

Daishi

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Oct 7th, 2005

Re: Help w/ for loop.

C++ Syntax (Toggle Plain Text)
#include <iostream>
 
using namespace std;
 
int main()
{
	int i, j, lines;
 
    cout << "This Program creates Christmas Trees." << endl;
 
	do
	{
		cout << "Please enter a number between 1 and 30" << endl;
		cin  >> lines; 
	}while (lines < 1 || lines > 30);
 
	for(j=1; j<=lines; j++)
	{
 
	   for(i=1; i<=lines; i++)
	   {
	      cout << " ";
	   }
 
	   for(i=1; i<=j; i++)
	   {
		  cout << "*";
	   }
	   cout << endl;
	}
}
#include <iostream>

using namespace std;

int main()
{
	int i, j, lines;

    cout << "This Program creates Christmas Trees." << endl;

	do
	{
		cout << "Please enter a number between 1 and 30" << endl;
		cin  >> lines; 
	}while (lines < 1 || lines > 30);

	for(j=1; j<=lines; j++)
	{

	   for(i=1; i<=lines; i++)
	   {
	      cout << " ";
	   }
	   
	   for(i=1; i<=j; i++)
	   {
		  cout << "*";
	   }
	   cout << endl;
	}
}

I tried but I'm still getting the same effect. What am I doing wrong? Is the second loop the problem now?

smallville

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Oct 7th, 2005

Re: Help w/ for loop.

I assume you have the left side of the christmas tree. What you need is the right side? You just need to print out twice as many stars in that case.

0: *
1: ***
2

****

-Fredric

Daishi

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Oct 9th, 2005

Re: Help w/ for loop.

[QUOTE=smallville]

C++ Syntax (Toggle Plain Text)
 
 
	for(j=1; j<=lines; j++)
	{
 
	   for(i=1; i<=lines; i++)
	   {
	      cout << " ";
	   }
 
	   for(i=1; i<=j; i++)
	   {
		  cout << "*";
	   }
	   cout << endl;
	}
}

	for(j=1; j<=lines; j++)
	{

	   for(i=1; i<=lines; i++)
	   {
	      cout << " ";
	   }
	   
	   for(i=1; i<=j; i++)
	   {
		  cout << "*";
	   }
	   cout << endl;
	}
}

the problem is with the for loops and the numbers you are using for the test program

if the first for loop
for(i=1; i<=lines; i++)
{
cout << " ";
}

the number for lines never changes so you are always moving over the same amount of spaces before printing out your stars... try making a temp variable that starts off equal to lines but decrements after both for loops are executed

the second for loop you want to print out stars that are double the amount you currently are; however, if you just simply attempt to print out double stars you will get a top of the tree that looks like this **
so you don't want just 2*j

drock9975

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Oct 11th, 2005

Re: Help w/ for loop.

man I've been racking my brains trying to fix this program without having to post so I would learn it but I have tried so many different ways in doing it and it still doesn't work for me

:cry:

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

I need it to not double but to add one to each line for however many lines you are asking the program to create.

C++ Syntax (Toggle Plain Text)
#include <iostream>
 
using namespace std;
 
int main()
{
	int i, j, lines;
 
    cout << "This Program creates Christmas Trees." << endl;
 
	do
	{
		cout << "Please enter a number between 1 and 30" << endl;
		cin  >> lines; 
	}while (lines < 1 || lines > 30);
 
	for(j=1; j<=lines; j++)
	{
 
	   for(i=1; i<=lines; i++)
	   {
	      cout << " ";
	   }
 
	   for(i=1; i<=j; i++)
	   {
		  cout << "*";
	   }
	   cout << endl;
	}
}
#include <iostream>

using namespace std;

int main()
{
	int i, j, lines;

    cout << "This Program creates Christmas Trees." << endl;

	do
	{
		cout << "Please enter a number between 1 and 30" << endl;
		cin  >> lines; 
	}while (lines < 1 || lines > 30);

	for(j=1; j<=lines; j++)
	{

	   for(i=1; i<=lines; i++)
	   {
	      cout << " ";
	   }
	   
	   for(i=1; i<=j; i++)
	   {
		  cout << "*";
	   }
	   cout << endl;
	}
}

smallville

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Oct 11th, 2005

Re: Help w/ for loop.

Try putting in "\s" instead of " " but that might just be a php thing.

Dulaithol

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