NEED homework help! Printing out patterns.

[omGeeK]

Okay, so i just started programming a week ago and i know some stuff but am completely stumped with this.

I can print out this pattern easy, where "-" = spaces

*******
-******
--*****
---****
----***
---****
--*****
-******
*******

by doing

	for(r=0;r<9;r++)
	{
		if(r<5)
		{
			m=1;
			b=0;
			m1=-1;
			b1=7;
		}
		else
		{
			m=-1;
			b=8;
			m1=1;
			b1=-1;
		}
			for(s=0;s<(m*r)+b;s++)
			printf(" ");
			for(c=0;c<(m1*r)+(b1);c++)
			printf("*");
			printf("\n");
                 }

but i cannot seem to do,

************************* 25
**************** 16
********* 9
**** 4
* 1

		for(r=0;r<5;r++)
	{
		for(c=0;c<(r^2)+(-10*r)+25;c++)
			printf("*");
			printf("\n");
	}

i tried using a quadratic formula to find the slope instead of y=mx+b. but it didnt print out right. Any help would be kind.

[kermit]

You do know that ^ is the bitwise exclusive or operator in C, right? It is not the notation for raising a number to a power.

[omGeeK]

umm yea just realized i put this in the wrong forum i am using c++ so yea

[kermit]

No worries at all. ^ is the bitwise exclusive or operator in C++ as well.

[omGeeK]

lol okay then well maybe thats were i messed up, so what should i use.

[kermit]

You can #include <math.h> (<cmath> for C++) and call the pow() function.

• C reference for pow()
• C++ reference for pow()

In this case, I would probably just multiply the number by itself though.

[omGeeK]

problem solved, simply did (r*r). thanks a bunch

[Swarvy]

Is there any reason why in this case you have a loop counting up from zero when a loop counting down would make more sense?

e.g.

int i,j;
for(i = 5; i >= 0; i--)
{
        for(j=0; j <= i*i; j++)
        {
                 printf("*");
         }
}

Just makes the expression in the inner loop a bit less confusing.

[omGeeK]

no reason at all, just how i was taught so i kinda got used to it.