Sirul lui Fibonacci

Acest sir consta in formula f(n)=f(n-2)+f(n-1), unde f(1)=1 si f(2)=1. f reprezinta o functie.

• Afisarea primilor n termeni

-vom nota f(n-2) cu a, f(n-1) cu b si f(n) cu c.

In C++, programul arata astfel:

int a,b,c,n,i;
cin>>n;
if(n==1)cout<<1;
else if(n==2) cout<<1<<” “<<1;
else
{
a=1;b=1;
cout<<a<<” “<<b<<” “;
for(i=3;i<=n;i++)
{
c=a+b;
a=b;
b=c;
cout<<c<<” “;
}
}

• Afisarea celui mai mare termen mai mic decat x

In C++, progrmaul arata astfel:

int x,a,b,c;
cin>>x;
a=b=1;
while(a+b<x)
{
c=a+b;
a=b;
b=c;
}
cout<<c;

• Scrierea unui numar ca suma de termeni ai sirului

In C++, programul arata astfel:

int n,a,b,c;
cin>>n;
while(n>0)
{
a=0;b=1;
while(a+b<=n)
{
c=a+b;
a=b;b=c;
}
cout<<c<<” “;
n=n-c;
}