C program Fibonacci series and Fibonacci number

This C program prints Fibonacci number series to a given number x. The Fibonacci series starts with two number 0 and 1, and then successive numbers are find by its previous two number in the series.

Fibonacci series

    start F.series = {0,1}

   next number in the series
     F.series = {0,1,0+1}

   next number in the series
     F.series = {0,1,1,1+1}

   next number in the series
     F.series = {0,1,1,2,1+2}    

  process continue till next number < x      
 

Fibonacci series - C program

The C program read a integer value x from user and then prints fibonacci series numbers less than integer value x.

 

#include <stdio.h>
int main() {

    int x=0; 
    int cF=0,pF=1;               
    printf("\n print Fibonacci series");
 
 printf("\nEnter value x :");
 scanf("%d",&x); 
 
 printf("\n Fibonacci Series :");
 
 do {
      printf( "%d ",cF);
      cF= cF + pF;      
      pF=cF-pF;                  
     } while (cF < x );
               
        return 0;
 }

Output

  print Fibonacci series
  Enter value x : 15

  Fibonacci Series : 0 1 1 2 3 5 8 13

It is a C program which finds n_th Fibonacci number using recursive function call. The program answers to the question what is value of 7th fibonacci number.

Fibonacci number

    int series(f)
     {
       if( f<=1)
           return f;   
       return ( series(f-1) +  series(f-2) )
     }

Fibonacci number recursive function - C programming code

The C program read a integer value n from user and then finds n_th Fibonacci number.

 

#include <stdio.h>

   int series(int f) {
  
  if (f ==0) 
     return 0;
  else if (f==1) 
     return 1;
  else
    return (series(f-1) + series(f-2));
 }
 
int main() {

    int n=0;  
    printf("\n Find nth Fibonacci number ");
 
 printf("\nEnter value for n :");
 scanf("%d",&n); 
  
 printf ( " nth fibonacci number is: %d " ,series(n-1));
   return 0;
 }
 

Fibonacci number - c program output

 Find nth Fibonacci number

 Enter value for n
 10
 
 nth fibonacci number is : 34

Download c program source code

• Fibonacci series
• Fibonacci number using recursive