I need help writing a program using Fibonacci sequence

The program needs to ask for n and then output the first n terms of the Fibonacci sequence.

exp.
n = 6
1, 1, 2, 3, 5, 8
1+1 =2
2+1=3
3+2=5
5+3=8

My origional program used a nested for loop.
I am not sure if that is right to use in this type a situation.
I would like suggestions to make it work.

#include

using namespace std;
int main ()
{
int fOne = 1;
int fTwo = 1;
int fThree = 2;
long fN;
long fNN;

cout << "How many n terms do you want in the sequence: ";
cin >> fN;

for ( fN = 1 ; fN >= 3 ; fN++ )
{
for (fNN = 1; fNN >= fN; fNN++)
fNN = (fN - 1) + (fN - 2);
cout << fN;
}
}

gpleonar

Newbie Poster

2 posts since Oct 2004

Reputation Points: 10

Solved Threads: 0

7 Years Ago

0

You have some mistakes in this code:
cin >> fN;

for ( fN = 1 ; fN >= 3 ; fN++ )
As you introducefN from the standard input, why are you initializing it in the for loop? More, if you are initializing fN = 1, then the condition in for loop fN >= 3 is never accomplished.

Then, for the Fibonacci series, as I know, every term of the series, starting with the third term, is the sum of the 2 preceding terms. In a vector, this should be a[n] = a[n-1] + a[n-2], right?
Or, in the for loop

for (fNN = 1; fNN >= fN; fNN++)
    fNN = (fN - 1) + (fN - 2);
cout << fN;

you are adding the same term, subtracting from it first 1, then 2..this is not exactly what you want...

frrossk

Posting Whiz in Training

220 posts since Sep 2004

Reputation Points: 17

Solved Threads: 9

7 Years Ago

0

Here you have some sample code:

#include <iostream> 

using namespace std;
int main ()
{
int a[128];
int fN;
int i;

a[0]=1;
a[1]=1;

cout << "How many n terms do you want in the sequence: ";
cin >> i;

for ( fN = 2 ; fN <= i ; fN++ )
{
a[fN]=a[fN-1]+a[fN-2];
cout << a[fN] <<"\n";
}
}

It has some limitations (you can't enter a value >128, for example), but I hope you get the idea.

frrossk

Posting Whiz in Training

220 posts since Sep 2004

Reputation Points: 17

Solved Threads: 9

5 Years Ago

0

Okay, when I ran this program, I saw one error:
1. I did not see the first two ones in the Fibonacci sequence.

Also, can you tell me that the a and the i means in this program??

naya22

Light Poster

48 posts since Apr 2007

Reputation Points: 24

Solved Threads: 0

5 Years Ago

0

>1. I did not see the first two ones in the Fibonacci sequence.
Probably because those values weren't printed. They're in the generated sequence though. frrossk's program kind of sucks anyway.

>Also, can you tell me that the a and the i means in this program??
a is an array that holds each number in the sequence and i is the expected length of the sequence.

Narue

Bad Cop

Administrator

15,460 posts since Sep 2004

Reputation Points: 6,464

Solved Threads: 1,401

5 Years Ago

0

> Nov 3rd 2004
> 2 Minutes Ago
Lets see, 2 and a half years.
Now, what was your question again?

Salem

Posting Sage

Team Colleague