""" This is a pure Python implementation of Dynamic Programming solution to the fibonacci sequence problem. """ class Fibonacci: def __init__(self, N=None): if N: N = int(N) self.fib_array = [0] * (N + 1) self.fib_array[0] = 0 self.fib_array[1] = 1 for i in range(2, N + 1): self.fib_array[i] = self.fib_array[ i - 1] + self.fib_array[i - 2] else: self.fib_array = [None] * (N + 1) def get(self, sequence_no=None): if sequence_no: if sequence_no < len(self.fib_array): return print(self.fib_array[:sequence_no]) else: print("Out of bound.") else: print("Please specify the a value") if __name__ == '__main__': import sys print("\n********* Fibonacci Series Using Dynamic Programming ************\n") # For python 2.x and 3.x compatibility: 3.x has not raw_input builtin # otherwise 2.x's input builtin function is too "smart" if sys.version_info.major < 3: input_function = raw_input else: input_function = input print("\n Enter the upper limit for the fibonacci sequence: ", end="") try: N = eval(input()) fib = Fibonacci(N) print( "\n********* Enter different values to get the corresponding fibonacci sequence, enter any negative number to exit. ************\n") while True: print("Enter value: ", end=" ") try: i = eval(input()) if i < 0: print("\n********* Good Bye!! ************\n") break fib.get(i) except NameError: print("\nInvalid input, please try again.") except NameError: print("\n********* Invalid input, good bye!! ************\n")