John and Ann sign up for Codewars

• Time : $O(n)$
• Space : $O(n)$

std::vector<long long> j{0}, a{1}, jpre{0}, apre{1};
class Johnann
{
    static void run(long long x) {
        while(j.size() <= x) {
            long long n = j.size();
            j.push_back(n - a[j.back()]);
            a.push_back(n - j[a.back()]);
            jpre.push_back(jpre.back() + j.back());
            apre.push_back(apre.back() + a.back());
        }
    }
public:
    static std::vector<long long> john(long long n) {
        run(n);
        std::vector<long long> res;
        for(long long i = 0; i < n; i++) res.push_back(j[i]);
        return res;
    }
    static std::vector<long long> ann(long long n) {
        run(n);
        std::vector<long long> res;
        for(long long i = 0; i < n; i++) res.push_back(a[i]);
        return res;
    }
    static long long sumJohn(long long n) {
        run(n);
        return jpre[n-1];
    }
    static long long sumAnn(long long n) {
        run(n);
        return apre[n-1];
    }
};