#!/usr/bin/env python3

# MIT License
#
# Copyright (c) 2019 Arkadiusz Netczuk <dev.arnet@gmail.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#


import time


def fib_classic(num):
    if num < 1:
        return 0
    if num == 1:
        return 1
    return fib_classic(num - 1) + fib_classic(num - 2)


def fib_iter(num):
    if num < 1:
        return 0
    if num == 1:
        return 1
    prev2 = 1
    prev1 = 1
    for _ in range(2, num):
        curr = prev1 + prev2
        prev2 = prev1
        prev1 = curr
    return prev1


class Fib:

    def __init__(self):
        self.res = 0

    def result(self):
        return self.res

    def calc(self, num):
        self.res = fib_classic( num )
        return self.res


## ===========================================================================


if __name__ == '__main__':
    """ Spawns only single main process, no additional threads """

    fib_arg = 37

    refStartTime = time.time()

    results = fib_classic(fib_arg)

    refEndTime = time.time()

    refDur = refEndTime - refStartTime

    print("Result:", results)
    print("Reference duration:", refDur, "sec")

