In this article, we will compute the nth Fibonacci number.
A Fibonacci number is defined by the recurrence relation given below −
Fn = Fn-1 + Fn-2
With F0= 0 and F1 = 1.
First, few Fibonacci numbers are
We can compute the Fibonacci numbers using the method of recursion and dynamic programming.
Now let’s see the implementation in the form of Python script
#recursive approach def Fibonacci(n): if n<0: print("Fibbonacci can't be computed") # First Fibonacci number elif n==1: return 0 # Second Fibonacci number elif n==2: return 1 else: return Fibonacci(n-1)+Fibonacci(n-2) # main n=10 print(Fibonacci(n))
The scope of all the variables declared is shown below.
#dynamic approach Fib_Array = [0,1] def fibonacci(n): if n<0: print("Fibbonacci can't be computed") elif n<=len(Fib_Array): return Fib_Array[n-1] else: temp = fibonacci(n-1)+fibonacci(n-2) Fib_Array.append(temp) return temp # Driver Program n=10 print(fibonacci(n))
The scope of all the variables declared is shown below
In this article, we learned about the computation of nth Fibonacci number using recursion and dynamic programming approach.