Submission #564451

#	Time	Username	Problem	Language	Result	Execution time	Memory
564451		Stickfish	Intergalactic ship (IZhO19_xorsum)	C++17	37 / 100	2091 ms	2224 KiB

xorsum

#include <iostream>
#include <vector>
#include <bitset>
using namespace std;
using ll = long long;

const int MAXN = 1008;
const ll MOD = 1000000007;
const int MAXVAL = 128;
int a[MAXN];

void updt(bitset<MAXVAL>& bs, int t) {
    if (bs[bs._Find_first() ^ t])
        return;
    vector<int> it;
    for (int i = bs._Find_first(); i < MAXVAL; i = bs._Find_next(i)) {
        it.push_back(i ^ t);
    }
    for (auto i : it)
        bs[i] = 1;
}

ll pw(ll a, ll m) {
    if (!m)
        return 1;
    a %= MOD;
    if (m % 2)
        return a * pw(a, m - 1) % MOD;
    return pw(a * a, m / 2);
}

bool in(pair<int, int> sg, int i) {
    return sg.first <= i && i < sg.second;
}

signed main() {
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i)
        cin >> a[i];
    int q;
    cin >> q;
    vector<pair<pair<int, int>, int>> qrs(q);
    for (int i = 0; i < q; ++i) {
        cin >> qrs[i].first.first >> qrs[i].first.second >> qrs[i].second;
        --qrs[i].first.first;
    }
    ll ans = 0;
    for (int i = 0; i < n; ++i) {
        for (int j = i; j < n; ++j) {
            bitset<MAXVAL> bsi;
            bitset<MAXVAL> bsj;
            bitset<MAXVAL> bsij;
            bsi[a[i]] = bsj[a[j]] = bsij[0] = 1;
            for (auto [sg, x] : qrs) {
                bool ini = in(sg, i);
                bool inj = in(sg, j);
                if (ini && !inj) {
                    updt(bsi, x);
                } else if (!ini && inj)
                    updt(bsj, x);
                else if (ini && inj)
                    updt(bsij, x);
            }
            ll addans = 0;
            for (int xi = bsi._Find_first(); xi < MAXVAL; xi = bsi._Find_next(xi)) {
                for (int xj = bsj._Find_first(); xj < MAXVAL; xj = bsj._Find_next(xj)) {
                    for (int xij = bsij._Find_first(); xij < MAXVAL; xij = bsij._Find_next(xij)) {
                        if (i != j)
                            addans += 2ll * (xi ^ xij) * (xj ^ xij);
                        else
                            addans += 1ll * (xi ^ xij) * (xj ^ xij);
                        addans %= MOD;
                    }
                }
            }
            addans *= (i + 1) * (n - j);
            addans %= MOD;
            addans *= pw(2, q);
            addans %= MOD;
            //cout << bsi.count() << ' ' << bsj.count() << ' ' << bsij.count() << endl;
            addans *= pw(bsi.count() * bsj.count() * bsij.count(), MOD - 2);
            ans += addans;
            ans %= MOD;
            //cout << i << ' ' << j << ": " << ans - ans0 << endl;
        }
    }
    cout << ans << endl;
}

• Subtask 1: 4 / 4
• Subtask 2: 5 / 5
• Subtask 3: 0 / 6
• Subtask 4: 9 / 9
• Subtask 5: 8 / 8
• Subtask 6: 11 / 11
• Subtask 7: 0 / 19
• Subtask 8: 0 / 30
• Subtask 9: 0 / 8