Before going to the program first let us understand what is a Fibonacci Series?
Fibonacci Series:
Fibonacci series is nothing but a Series of Numbers which are found by adding the two preceding(previous) Numbers.
For Example,
0,1,1,2,3,5,8,13,21 is a Fibonacci Series of length 9.
For more understanding you can check out the following link:
https://www.mathsisfun.com/numbers/fibonacci-sequence.html
Program code to Display Fibonacci Series in C:
#include<stdio.h>
#include<conio.h> void main()
{ int n,f,f1=-1,f2=1; clrscr(); printf(" Enter The Number Of Terms:"); scanf("%d",&n); printf(" The Fibonacci Series is:"); do { f=f1+f2; f1=f2; f2=f; printf(" n %d",f); n--; }while(n>0); getch();
}
Related: Fibonacci Series in C++ using Do-While Loop
Working:
- First the computer reads the value of number of terms for the Fibonacci series from the user.
- Then using do-while loop the two preceding (previous) numbers are added and printed.
- The loop continues till the value of number of terms.
Step by Step working of the above Program Code:
Let us assume that the Number of Terms entered by the user is 5.
- It assigns the value of n=5.
- Then the loop continues till the condition of the do-while loop is true.
2.1. do
f=f1+f2 (f=-1+1) So f=0
f1=f2 (f1=1) So f1=1
f2=f (f2=0) So f2=0
print the value of “f” (ie. 0)
n – – (n=n-1) So n=4
n>0 (4>0), do-while loop condition is true
2.2. do
f=f1+f2 (f=1+0) So f=1
f1=f2 (f1=0) So f1=0
f2=f (f2=1) So f2=1
print the value of “f” (ie. 1)
n – – (n=n-1) So n=3
n>0 (3>0), do-while loop condition is true
2.3. do
f=f1+f2 (f=0+1) So f=1
f1=f2 (f1=1) So f1=1
f2=f (f2=1) So f2=1
print the value of “f” (ie. 1)
n – – (n=n-1) So n=2
n>0 (2>0), do-while loop condition is true
2.4. do
f=f1+f2 (f=1+1) So f=2
f1=f2 (f1=1) So f1=1
f2=f (f2=2) So f2=2
print the value of “f” (ie. 2)
n – – (n=n-1) So n=1
n>0 (1>0), do-while loop condition is true
2.5. do
f=f1+f2 (f=1+2) So f=3
f1=f2 (f1=2) So f1=2
f2=f (f2=3) So f2=3
print the value of “f” (ie. 3)
n – – (n=n-1) So n=0
n>0 (0>0), do-while loop condition is false
2.6. It comes out of the do-while loop.
- Thus the program execution is completed.
Output:
