Project Euler Problem 2

问题：

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.

答案：4613732

#include

int main(void)
{
        long int sum=0L, limit=4000000L, a=1L, b=1L, c=2L;

        while(c        {
                sum+=c;
                a=b+c;
                b=c+a;
                c=a+b;
        }
        printf("%li\n", sum);
        return 0;
}