gistfile1.py

''' take from python.org example, using hot_swapping variables method '''
def fib_hotswap(n):
    a = 1
    b = 1
    for _ in range(1,n+1):
        tmp = a + b
        b = a
        a = tmp
    return b
  
''' take from class' note ICS 33 example, using recursive method '''
def fib_recursive(n):
    assert n>=0, 'fib cannot have negative n('+str(n)+')'
    if    n == 0: return 1
    elif  n == 1: return 1
    else:         return fib_recursive(n-1) + fib_recursive(n-2)

cache = {}
cache[0] = 1
cache[1] = 1
  
''' using cache '''
def fib_recursive_cache(n):
    assert n>=0, 'fib cannot have negative n('+str(n)+')'
    if n == 0: return cache[0]
    elif n == 1: return cache[1]
    elif n in cache: return cache[n]
    else:
        cache[n] = fib_recursive_cache(n-1) + fib_recursive_cache(n-2)
        return cache[n]

First calculation 35th number of Fibonacci -> 14930352

Mesuare time take for "hot swapping" method -> 5.6564998885733075e-05 seconds

Second calculation 35th number of Fibonacci -> 14930352

Mesuare time take for "recursive" method -> 4.214802125999995 seconds

Second calculation 35th number of Fibonacci -> 14930352

Mesuare time take for "recursive cache" method -> 4.5699000111198984e-05 seconds