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def recursiveFib(n):
if n == 1 or n == 2:
return 1
return recursiveFib(n - 1) + recursiveFib(n - 2)
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from functools import lru_cache
@lru_cache()
def recursiveFibCached(n):
if n == 1 or n == 2:
return 1
return recursiveFibCached(n - 1) + recursiveFibCached (n - 2)
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import sys
sys.setrecursionlimit(5000)
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def iterativeFib(n):
a, b = 0, 1
for i in range(n):
a, b = b, a + b
return a
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Python :
def formulaFib(n):
root_5 = 5 ** 0.5
phi = ((1 + root_5) / 2)
a = ((phi ** n) - ((-phi) ** -n)) / root_5
return round(a)
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. decimal, :
import decimal
def formulaFibWithDecimal(n):
decimal.getcontext().prec = 10000
root_5 = decimal.Decimal(5).sqrt()
phi = ((1 + root_5) / 2)
a = ((phi ** n) - ((-phi) ** -n)) / root_5
return round(a)
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