need help, please

[slickn_sly]

How would i go about implementing a program in java that would do the
following,

f(1) = 1; f(2) = 1; f(3) = 1; f(4) = 1; f(5) = 1;

f(n) = f( n - 1 ) + 3 * f( n - 5 ) for all n > 5

and display the results for n = 6, 7, 12, and 15

if someone can start me off, i would really appreciate it cause i'm
lost.

I know how to calulate the values on paper, but implementing a program
to do it is something else
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[Ryan Stewart]

"slickn_sly" <bn***@hotmail-dot-com.no-spam.invalid> wrote in message
news:41********@Usenet.com...

How would i go about implementing a program in java that would do the
following,

f(1) = 1; f(2) = 1; f(3) = 1; f(4) = 1; f(5) = 1;

f(n) = f( n - 1 ) + 3 * f( n - 5 ) for all n > 5

and display the results for n = 6, 7, 12, and 15

if someone can start me off, i would really appreciate it cause i'm
lost.

I know how to calulate the values on paper, but implementing a program
to do it is something else

*sniff sniff* Smells like homework. We don't do homework here. If you bring
some code to us, we'll be happy to help you straighten it out and figure out
whatever problems you run into. That said, if you can figure it out on
paper, you should be able to code it. Just break it down into the simplest
steps you can. For example, the first thing you might notice is that you
have one set of conditions for n <= 5 and another for n > 5. That's an if
statement if I've ever seen one:
if (n <= 5) {
...
} else {
...
}

Or if you prefer:
if (n > 5) {
...
} else {
...
}

That's your first "rule" governing the problem. Just break it down more from
there and fill in what you need. See http://www.physci.org/codes/sscce.jsp
for tips on posting your code to the ng for help.

Finally, please post to comp.lang.java.help in the future. This group is
deprecated.

[Casey Hawthorne]

In Python something that may be close:

def fibonacciSlow(n): if n==0:
return 0
elif n==1:
return 1
else:
return fibonacciSlow(n-1) + fibonacciSlow(n-2)

def fibonacciFastHelper(n, currFib, prevFib): if n==0:
return prevFib
elif n==1:
return currFib
else:
return fibonacciFastHelper(n-1, currFib + prevFib, currFib)

def fibonacciFast(n):

return fibonacciFastHelper(n, 1, 0)

--
Regards,
Casey

[slickn_sly]

I don't know if im in the right track

public static int f( int n )
{
if( n == 1 && n == 5 )
{
return 1;
}
else
{
return f( n - 1 ) + ( 3 * f( n - 5 ) );
}
}

public static void main( String[] args )
{
System.out.println( "f( 6 ) is equal to " + f( 6 ) );
}
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[-jit]

I think you got the idea.
There is something wrong with your basic condition.

if(n == 1 && n == 5) //What if n = 2? It will cause an infinite loop.

So it should be

if(n == 0) return 0;
if(n < 6) return 1;

-jit

slickn_sly wrote:

I don't know if im in the right track

public static int f( int n )
{
if( n == 1 && n == 5 )
{
return 1;
}
else
{
return f( n - 1 ) + ( 3 * f( n - 5 ) );
}
}

public static void main( String[] args )
{
System.out.println( "f( 6 ) is equal to " + f( 6 ) );
}
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[slickn_sly]

thanks everyone for all the help.

I think I have enough info to figure it out.
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