Even Fibonacci Numbers

Problem Link

Each Fibonacci number is the sum of the two numbers before it. This code builds the sequence up to four million and adds only the even numbers.

#include <iostream>
#include <vector>
using namespace std;
 
void solve(void) {
  vector<int> f(33, 1);
  for (int i=2; i<=32; i++) {
    f[i] = f[i-1] + f[i-2];
  }
 
  int ans = 0;
  for (int i=1; i<=32; i++) {
    if (!(f[i] % 2)) ans += f[i];
  }
  cout << ans;
}
 
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
 
  solve();
  return 0;
}