Python/project_euler/problem_02/sol5.py
Suad Djelili 8b572e6cfd added solution 7 for problem_01 (#1416)
* added solution 7 for problem_01

* added solution 5 for problem_02
2019-10-22 09:31:17 +02:00

47 lines
930 B
Python

"""
Problem:
Each new term in the Fibonacci sequence is generated by adding the previous two
terms. By starting with 1 and 2, the first 10 terms will be:
1,2,3,5,8,13,21,34,55,89,..
By considering the terms in the Fibonacci sequence whose values do not exceed
n, find the sum of the even-valued terms. e.g. for n=10, we have {2,8}, sum is
10.
"""
def solution(n):
"""Returns the sum of all fibonacci sequence even elements that are lower
or equals to n.
>>> solution(10)
10
>>> solution(15)
10
>>> solution(2)
2
>>> solution(1)
0
>>> solution(34)
44
"""
a = [0,1]
i = 0
while a[i] <= n:
a.append(a[i] + a[i+1])
if a[i+2] > n:
break
i += 1
sum = 0
for j in range(len(a) - 1):
if a[j] % 2 == 0:
sum += a[j]
return sum
if __name__ == "__main__":
print(solution(int(input().strip())))