"""Even Fibonacci numbers""" from euler import fibonacci #1. direct way print(sum(i for i in fibonacci(4000000) if i % 2 == 0)) #2. every third number is even
import argparse
import math
import euler
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Solves problem number 19 of Euler Project")
parser.add_argument("--limit", type=int, default=1000)
args = parser.parse_args()
for pos, fib in enumerate(euler.fibonacci()):
if fib >= 10 ** (args.limit - 1):
print pos + 1
break
#!/usr/bin/env python
# By considering the terms in the Fibonacci sequence whose values do
# not exceed four million, find the sum of the even-valued terms.
import euler
MAX = 4000000
num = 0
for x in euler.fibonacci():
if x > MAX:
break
elif x % 2 == 0:
num += x
print num
# /usr/bin/env/python
import time
from euler import fibonacci_n, fibonacci
from itertools import takewhile
start = time.time()
result = sum(x for x in fibonacci_n(4 * 10**6) if x % 2 == 0)
time_spend = time.time() - start
print "The sum is %s and take time is %f" % (result, time_spend)
start = time.time()
result = sum(x for x in takewhile(lambda x: x < 4 * 10**6, fibonacci())
if x % 2 == 0) # take while is helpful
time_spend = time.time() - start
print "The sum is %s and take time is %f" % (result, time_spend)
#!/usr/bin/env python
# What is the first term in the Fibonacci sequence to contain 1000
# digits?
import euler
i = 0
for x in euler.fibonacci():
i+=1
if len(str(x)) == 1000:
print i, x
break
import math from euler import fibonacci print sum(fib for fib in fibonacci(4000000) if fib%2 == 0)
def testSuccess(self):
expected = [1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
actual = itertools.islice(euler.fibonacci(), 10)
self.assertItemsEqual(expected, actual)
import math import itertools from euler import fibonacci def fib_term(n): phi = (1+math.sqrt(5))/2 return round(math.pow(phi, n)/math.sqrt(5)) for offset, num in enumerate(fibonacci()): length = len(str(num)) if length >= 1000: print offset+1 break
import euler import itertools fib = itertools.takewhile(lambda f: f < 4000000, euler.fibonacci()) print(sum(i for i in fib if i % 2 == 0))
"""1000-digit Fibonacci number"""
from euler import fibonacci
N = 1000
maximum = 10**1001
for idx, i in enumerate(fibonacci(maximum), start=2):
if len(str(i)) == N:
print '{}th term contains 1000 digits: \n{}'.format(idx, i)
break
import time
from euler import fibonacci
start = time.time()
result = 0
gen = fibonacci(10**1000)
i = 0
while True:
num = gen.next()
i += 1
if len(str(num)) > 999:
result = i
break
spend = time.time() - start
print "The result is %s and take time is %f" % (result, spend)
def first_Fib_N_digits(N):
for i, f in enumerate(fibonacci()):
if f >= 10 ** (N - 1):
return i + 1
