C++ Program to show Fibonacci Series

Write a C++ program , that prints all the Fibonacci numbers , which are smaller than or equal to a number k(k≥2) ,which was entered by the user.

• The Fibonacci numbers are a sequence of numbers,where then-th number of Fibonacci is defined as:
• Fib(0)=0,
• Fib(1)=1,
• Fib(n)=Fib(n-1)+Fib(n-2) Usage :> Input of k:21 > Fibonacci numbers<=21:01123581321

Solution 1 –

The solution below will answer following questions :
1. Write a program to generate the Fibonacci series in C++.
2. Fibonacci series in C++ using for loop.
3. How to print Fibonacci series in C++.
4. Write a program to print Fibonacci series inC++.
5. How to find Fibonacci series in C++ programming.
6. Basic C++ programs Fibonacci series.

```#include<iostream>

using namespace std;

int main (void)
{

int r=0,a=0,n,b=1,i,c;
char redo;
do
{
a=0;
b=1;
cout<<"enter the the value of n:";
cin>> n;
if(n>100){
cout<<"enter some lessor value"<<endl;
}
else{
cout<<a<<endl;
for (i=0;i<=n;i++)
{
c=a+b;
a=b;
b=c;
cout<<"serial no."<<i+1<<"==";
cout<<a <<endl;
}
cout<<"enter y or Y to continue:";
cin>>redo;
cout<<endl<<endl;
}
}
while(redo=='y'||redo=='Y');

return 0;
}
```

Solution 2 –

If we want to Write a program to generate the Fibonacci series in C++ using recursion, the follow the solution below :

```/**
Fibonacci series in C++ using recursion by codebind.com
*/

#include <iostream>

int Fibonacci(int x) {
if (x < 2){
return x;
}
return (Fibonacci (x - 1) + Fibonacci (x - 2));
}

int main(void) {
int number;
std::cout << "Please enter a positive integer: ";
std::cin >> number;
if (number < 0)
std::cout << "That is not a positive integer.\n";
else
std::cout << number << " Fibonacci is: " << Fibonacci(number) <<  std::endl;
return 0;
}
```

Solution 3 –

The solution below will answer following questions :
1. Fibonacci series using array in C++
2. Fibonacci series program in C++ language
3. Source code of Fibonacci series inC++
4.Write a program to print Fibonacci series in C++

```/**
Fibonacci series in C++ using array by codebind.com
*/

#include <iostream>

int main(void) {
int i,number;
long int arr[40];

std::cout << "Enter the number : "<< std::endl;
std::cin >> number;

arr[0]=0;
arr[1]=1;

for(i = 2; i< number ; i++){
arr[i] = arr[i-1] + arr[i-2];
}

std::cout << "Fibonacci series is: ";
for(i=0; i< number; i++)
std::cout << arr[i] << std::endl;
return 0;
}```