Fibonacci series C++ Program

Fibonacci series program in C++

Fibonacci series is a series in which the next term is the sum of the previous two numbers. Here, we’ll write a program to print the Fibonacci series on the basis of series elements to be printed.

Fibonacci Series: 0, 1, 1, 2, 3, 5, 8, 13, 21

Logic:

We will take two variables with values 0 and 1. Then a third var which will be the sum of the first two var and then loop through it.

Algorithm:

1. Take the input for the series of elements to be printed.
2. Take two variables, pre and next and assign pre = 0 and next = 1.
3. Take another variable, last which will be the sum of pre and next.
4. Run a while loop.
5. Print the value of pre.
6. Change the values of pre, next and last in the loop.
7. End loop after n iterations.

Code:

#include<iostream>
using namespace std;
int main()
{
	int n,pre,next,last;
	cout<<"How many numbers of fibonacci series do you want to print?";
	cin>>n;
	pre=0;		//previous number
	next=1;		//next number
	last=pre+next;
	while(n>0)
	{
		cout<<"\n"<<pre;
		pre=next;      //pushing the three values ahead
		next=last;
		last=pre+next; //third number is sum of new first and second number
		n--;
	}
	return 0;
}

Output:

How many numbers of Fibonacci series do you want to print? 10
0
1
1
2
3
5
8
13
21
34