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fibonacci.py
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60 lines (50 loc) · 1.46 KB
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# source: http://oeis.org/A000045
fibo_seq = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610,
987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025,
121393, 196418, 317811, 514229, 832040, 1346269, 2178309,
3524578, 5702887, 9227465, 14930352, 24157817, 39088169]
from functools import lru_cache
def fibonacci(n):
if n < 2:
return n
return fibonacci(n-2) + fibonacci(n-1)
@lru_cache()
def fibonacci2(n):
if n < 2:
return n
return fibonacci2(n-2) + fibonacci2(n-1)
def memoize(func):
'''simplest memoizing decorator'''
cache = {}
def memoized(*args):
if args not in cache:
cache[args] = func(*args)
return cache[args]
return memoized
def test():
for i, expected in enumerate(fibo_seq[:31]):
print(i, expected)
assert fibonacci(i) == expected
def chronograph():
global fibonacci
from time import time
t0 = time()
n = 32
res = fibonacci(n)
#res = [fibonacci(n) for n in range(30)]
t1 = time()
print(n, res, format(t1-t0, '0.6f'))
t0 = time()
res = fibonacci2(n)
#res = [fibonacci2(n) for n in range(30)]
t1 = time()
print(n, res, format(t1-t0, '0.6f'))
t0 = time()
fibonacci = memoize(fibonacci)
res = fibonacci(n)
#res = [fibonacci2(n) for n in range(30)]
t1 = time()
print(n, res, format(t1-t0, '0.6f'))
if __name__=='__main__':
#test()
chronograph()