P.E.2: Even Fibonacci numbers

Here's my C++ code

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#include<iostream>
#include<cstdio>
#define limit 4000000
using namespace std;
int main()
{
    long long int a=1,b=2,c;
    double sum=2;
    while(1)
    {
        c=a+b;
        if(c>limit)
            break;
        if(c%2==0)
            sum+=(double)c;
        a=b;
        b=c;
    }
    printf("%.0lf",sum);
    return 0;
}

0.000314 second evaluation time using Python:

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memo = {1:1,2:1}
def fib(n):
    if n in memo:
        return memo[n]
    memo[n] = fib(n - 1) + fib(n - 2)
    return memo[n]
total = 0
i = 1
while fib(i) <= 4000000:
    if fib(i) % 2 == 0:
        total += fib(i)
    i += 1
print "Answer:", total

My Python code goes as follows:

"""
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.
"""
sum = 0
x, y = 0, 1
while y < 4000000:
    x, y = y, x + y
    if x % 2:
        continue
    sum = sum + x

print "The sum of the even valued terms in a fibonacci sequence less than 4 million is:"
print sum

Hope this helps!