In this C++ tutorial, you will learn how to write a C++ program to generate Fibonacci series, and print them. We will cover programs to generate Fibonacci series using While loop, Do-while loop, and For loop.
C++ Fibonacci Series
Fibonacci Series is a series in which the current element is equal to the sum of two immediate previous elements. Fibonacci series start with 0 and 1, and progresses.
Algorithm to Generate Fibonacci Series
You can use following algorithm to generate a Fibonacci Series using looping technique.
- Start.
- Take a variable
n
. We have to generaten
items of Fibonacci series. - Create an Array
fibo[]
with the size ofn
. - Take
index
with initial value of zero. - Check if
index
is less thann
. If false go to step 11. - If index is
0
, assign fib[index] with0
. Go to step 9. - If index is
1
, assign fib[index] with1
. Go to step 9. - Assign
fibo[index]
with the sum of previous two elementsfibo[index-1]
andfibo[index-2]
. - Increment
index
. Go to step 5. - Print
fibo[]
. - Stop.
Fibonacci Series using While loop
In the following program, we shall use C++ While Loop to generate Fibonacci Series.
C++ Program
#include <iostream> using namespace std; int main() { int n = 10; int fibo[n]; //generate fibonacci series int index = 0; while (index < n) { if (index == 0) fibo[index] = 0; else if (index == 1) fibo[index] = 1; else fibo[index] = fibo[index - 1] + fibo[index - 2]; index++; } //print fibonacci series for (int i = 0; i < n; i++) cout << fibo[i] << " "; }
Output
0 1 1 2 3 5 8 13 21 34
Fibonacci Series using Do-while loop
In the following program, we shall use C++ Do-while Loop to generate Fibonacci Series.
C++ Program
#include <iostream> using namespace std; int main() { int n = 15; int fibo[n]; //generate fibonacci series int index = 0; do { if (index == 0) fibo[index] = 0; else if (index == 1) fibo[index] = 1; else fibo[index] = fibo[index - 1] + fibo[index - 2]; index++; } while (index < n); //print fibonacci series for (int i = 0; i < n; i++) cout << fibo[i] << " "; }
Output
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377
Fibonacci Series using For loop
In the following program, we shall use C++ For Loop to generate Fibonacci Series.
C++ Program
#include <iostream> using namespace std; int main() { int n = 10; int fibo[n]; //generate fibonacci series for (int index = 0; index < n; index++) { if (index == 0) fibo[index] = 0; else if (index == 1) fibo[index] = 1; else fibo[index] = fibo[index - 1] + fibo[index - 2]; } //print fibonacci series for (int i = 0; i < n; i++) cout << fibo[i] << " "; }
Output
0 1 1 2 3 5 8 13 21 34
Conclusion
In this C++ Tutorial, we learned how to generate a Fibonacci series using looping techniques in C++.