Problem 2(Even Fibonacci numbers)

Problem 2(Even Fibonacci numbers)

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 four million, find the sum of the even-valued terms.

In Python:

i=1
limit=4000000
sum=0

def fibonacci(n):
if n==1:
return 1
elif n==2:
return 2
else:
return fibonacci(n-2)+fibonacci(n-1)

while fibonacci(i)<limit:
if fibonacci(i)%2==0:
sum+=fibonacci(i)
i+=1

print(sum)

Run time: 5.832750082015991 seconds

In Java:

package project_euler;

public class Euler2 {

public static void main(String[] args) {

int i = 1;

int limit = 4000000;

int sum = 0;

long startTime = System.currentTimeMillis();

while (fibonacci(i) < limit) {

if (fibonacci(i) % 2 == 0) {

sum += fibonacci(i);

}

i++;

}

long endTime = System.currentTimeMillis();

System.out.println(sum);

System.out.println((double)(endTime - startTime)/(double)1000 +"seconds");

System.out.println((endTime - startTime) +"ms");

}

public static int fibonacci(int n) {

if(n==1) {

return 1;

}else if (n==2) {

return 2;

}

else {

return fibonacci(n-1)+fibonacci(n-2);

}

}

}

Run time: 0.084seconds

solution: 4613732

[from Project Euler: https://projecteuler.net/problem=2]