Fibonacci Series Program in C (Iteration)
In this method, we use one of the C loops to iterate and print the current term. The first two terms, F1 and F2 are handled separately. After that, we use two variables to store the previous two terms and keep updating them as we move to print the next term.
C
// C Program to print the fibonacci series using iteration // (loops) #include <stdio.h> // function to print fibonacci series void printFib( int n) { if (n < 1) { printf ( "Invalid Number of terms\n" ); return ; } // when number of terms is greater than 0 int prev1 = 1; int prev2 = 0; // for loop to print fibonacci series for ( int i = 1; i <= n; i++) { if (i > 2) { int num = prev1 + prev2; prev2 = prev1; prev1 = num; printf ( "%d " , num); } // for first two terms if (i == 1) { printf ( "%d " , prev2); } if (i == 2) { printf ( "%d " , prev1); } } } // driver code int main() { int n = 9; printFib(n); return 0; } |
0 1 1 2 3 5 8 13 21
Complexity Analysis
Time Complexity: O(n), Because for n number for terms, the loop inside the printFib() function will be executed n times.
Space Complexity: O(1), Because we only used a few variables which don’t depends on the number of terms to be printed.
For more details, refer to the complete article – Program to Find and Print Nth Fibonacci Numbers
Fibonacci Series Program in C
In this article, we will discuss the Fibonacci series and the programs to print the Fibonacci series in C using recursion or loops.