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Fibonacci series C program

Fibonacci series in C programming: C program for Fibonacci series using a loop and recursion. Using the code below you can print as many terms of the series as required. Numbers of this sequence are known as Fibonacci numbers. The first few numbers of the series are 0, 1, 1, 2, 3, 5, 8, ...,. Except for the first two terms of the sequence, every other term is the sum of the previous two terms, for example, 8 = 3 + 5 (addition of 3 and 5). This sequence has many applications in Mathematics and Computer Science.

Fibonacci series C program using for loop

/* Fibonacci series program in C language */
#include<stdio.h>
 
int main()
{
   int n, first = 0, second = 1, next, c;
 
   printf("Enter the number of terms\n");
   scanf("%d",&n);
 
   printf("First %d terms of Fibonacci series are :-\n",n);
 
   for ( c = 0 ; c < n ; c++ )
   {
      if ( c <= 1 )
         next = c;
      else
      {
         next = first + second;
         first = second;
         second = next;
      }
      printf("%d\n",next);
   }
 
   return 0;
}

Output of program:
Fibonacci series C program output

Fibonacci series C program using recursion

#include<stdio.h>
 
int f(int);
 
main()
{
   int n, i = 0, c;
 
   scanf("%d",&n);
 
   printf("Fibonacci series:\n");
 
   for ( c = 1 ; c <= n ; c++ )
   {
      printf("%d\n", f(i));
      i++; 
   }
 
   return 0;
}
 
int f(int n)
{
   if ( n == 0 )
      return 0;
   else if ( n == 1 )
      return 1;
   else
      return ( f(n-1) + f(n-2) );
} 

The recursive method is less efficient as it involves repeated function calls and there are chances of stack overflow as the function will frequently be called if calculating larger Fibonacci numbers.