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 four million, find the sum of the even-valued terms.
Sol. 1
#include <stdio.h>
int main() {
int n = 0;
int sum = 0;
int i = 1;
int j = 2;
int temp;
scanf("%d", &n);
while (j <= n) {
if ((j & 1) == 0) //can also use(j%2 == 0)
sum += j;
temp = i;
i = j;
j = temp + i;
}
printf("%d\n", sum);
}