Page 174 - DCAP407_DATA_STRUCTURE

Unit 9: Recursion

/* Fibonacci recursion function */
long fibonacci (long n)
{
/* Check if the value of n is equal to 1 */

if (n==1)
{
/* Return 0 */
return 0;
}
/* Check if the value of n is equal to 2 */
if (n==2)
{

/* Return 1 */
return 1;
}
/* Otherwise */
else
{

/* Fibonacci function is invoked within itself and the value is returned */
return fibonacci (n-1) + fibonacci (n-2);
}
}
Output:
Input an integer: 5
Fibonacci (5) = 0, 1, 1, 2, 3

In this example:
1. First, the stdio.h header file is included using the include keyword.
2. Then, fibonacci function is declared globally. It returns and accepts a long
data type.
3. Then, the int main (void) program is defined. This returns an integer value.
4. In main ():

(a) First, initialize the long variables result and number.
(b) Then, accept the value for number.
(c) Then, call the fibonacci function and store its value in a variable result.
(d) Then, print the value of result.
(e) Finally, return the value 0.

5. Then the function fibonacci is defined.

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