subset sum solver

#include <iostream>
#include <unordered_map>
using namespace std;

typedef long long int ll;

const ll goal = 3407298087646051ll;
const ll N = 48;
const ll limit = 1 << (N/2);
const ll first_half[N] = {
    26202120271102ll, 135428455329960ll, 226145215191180ll, 38455307198310ll,
    158395314926886ll, 277270108468340ll, 38078189488823ll, 7031915446272ll,
    247000637688469ll, 228977091817671ll, 256367647107166ll, 190531347466612ll,
    206895433573789ll, 168781003454738ll, 28930412047822ll, 188583634192561ll,
    34220655142866ll, 126339871758705ll, 186833711857971ll, 40038576937759ll,
    257739027555181ll, 191847862752289ll, 49450796464709ll, 94828960768221ll
};
const ll second_half[N] = {
    26429280575443ll, 141300452697398ll, 89608755458014ll, 24069321165527ll,
    269955250224311ll, 137049179130697ll, 30013333805191ll, 45524295173439ll,
    259726767088158ll, 62421348646183ll, 226835227234443ll, 8307450244249ll,
    115379801108132ll, 164730692261102ll, 72682278146483ll, 48841420576159ll,
    48754324556907ll, 157844925781173ll, 177587100004140ll, 151008742623371ll,
    251706689387188ll, 32611554746822ll, 43532371092965ll, 5830775211360ll
};

int main() {
    unordered_map<ll, ll> second_half_goals;
    for(ll i = 0; i < limit; i++) {
        ll k = i;
        ll u = 0;
        ll subset_sum = 0;
        while(k > 0) {
            if(k % 2) {
                subset_sum += first_half[u];
            }
            k /= 2; u++;
        }
        second_half_goals[goal - subset_sum] = i;
    }
    for(ll j = 0; j < limit; j++) {
        ll k = j;
        ll u = 0;
        ll subset_sum = 0;
        while(k > 0) {
            if(k % 2) {
                subset_sum += second_half[u];
            }
            k /= 2; u++;
        }
        if(second_half_goals.count(subset_sum)) {
            ll i = second_half_goals[subset_sum];
            cout << "Found answer " << i << " " << j << "\n";
        }
    }
    return 0;
}