# Program for Fibonacci numbers in C

Given with ‘n’ numbers the task is to generate the fibonacci series till starting from 0 to n where fibonacci series of integer is in the form

0, 1, 1, 2, 3, 5, 8, 13, 21, 34

Where, integer 0 and 1 will have fixed space, after that two digits are added for example,

0+1=1(3rd place)
1+1=2(4th place)
2+1=3(5th place) and So on

Sequence F(n) of fibonacci series will have recurrence relation defined as −

Fn = Fn-1 + Fn-2
Where, F(0)=0 and F(1)=1 are always fixed

There can be multiple approaches that can be used to generate the fiboacce series −

Recursive approach − in this, approach function will make a call to itself after every integer value. It is simple and easy to implement but it will lead to exponential time complexity which makes this approach ineffective.

Using For Loop − By using For loop in generating Fibonacci series time complexity can be reduced to O(n) which makes this approach effective.

## Example

Input-: n=10
Output-: 0 1 1 2 3 5 8 13 21 34

## Algorithm

Start
Step 1 -> Declare function for Fibonacci series
Void Fibonacci(int n)
Declare variables as int a=0,b=1,c,i
Print a and b
Loop For i=2 and i<n and ++i
Set c=a+b
Print c
Set a=b
Set b=c
End
Step 2 -> In main()
Declare int as 10
Call Fibonacci(n)
Stop

## Example

#include<stdio.h>
void fibonacci(int n){
int a=0,b=1,c,i;
printf("fibonacci series till %d is ",n);
printf("%d %d",a,b);//it will print 0 and 1
for(i=2;i<n;++i) //loop starts from 2 because 0 and 1 are the fixed values that series will take{
c=a+b;
printf(" %d",c);
a=b;
b=c;
}
}
int main(){
int n=10;
fibonacci(n);
return 0;
}

## Output

fibonacci series till 10 is
0 1 1 2 3 5 8 13 21 34