Fibonacci numbers

Explanation of the Code

1. Reading Input:
   n = int(input())

   • The input() function reads a line of text from the user.
   • The int() function converts this input to an integer and stores it in the variable n.
2. Handling Base Cases:
   if n == 0:


       print(0)


   elif n == 1:


       print(1)

   • If $n$ is 0, print 0.
   • If $n$ is 1, print 1.
3. Calculating Fibonacci Number Using a For Loop:
   else:


       fib_0 = 0


       fib_1 = 1


       for _ in range(2, n + 1):


           fib_n = fib_0 + fib_1


           fib_0 = fib_1


           fib_1 = fib_n


       print(fib_n)

   • Initialize fib_0 to 0 and fib_1 to 1.
   • Use a for loop to iterate from 2 to $n$.
   • In each iteration, calculate the next Fibonacci number (fib_n) as the sum of the previous two Fibonacci numbers.
   • Update fib_0 to the value of fib_1 and fib_1 to the value of fib_n.
   • After the loop, print the value of fib_n.