#956303 (C++17) No.5020 Averaging

• 問題: No.5020 Averaging
• ユーザー: wanui
• 提出日時: 2024-02-29 02:50:34
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 674 ms / 1,000 ms
• コード長: 8,141 bytes
• コンパイル時間: 3,443 ms
• コンパイル使用メモリ: 231,656 KB
• 実行使用メモリ: 46,172 KB
• スコア: 85,171,817
• 最終ジャッジ日時: 2024-02-29 02:51:17
• 合計ジャッジ時間: 36,334 ms
• ジャッジサーバーID （参考情報）: judge13 / judge15

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	613 ms; 46,172 KB
testcase_01	AC	659 ms; 46,172 KB
testcase_02	AC	641 ms; 46,172 KB
testcase_03	AC	590 ms; 44,124 KB
testcase_04	AC	546 ms; 44,124 KB
testcase_05	AC	629 ms; 46,172 KB
testcase_06	AC	656 ms; 46,172 KB
testcase_07	AC	655 ms; 46,172 KB
testcase_08	AC	591 ms; 44,124 KB
testcase_09	AC	657 ms; 46,172 KB
testcase_10	AC	618 ms; 46,172 KB
testcase_11	AC	590 ms; 44,124 KB
testcase_12	AC	566 ms; 44,124 KB
testcase_13	AC	582 ms; 46,172 KB
testcase_14	AC	580 ms; 44,124 KB
testcase_15	AC	642 ms; 44,124 KB
testcase_16	AC	539 ms; 44,124 KB
testcase_17	AC	605 ms; 44,124 KB
testcase_18	AC	635 ms; 46,172 KB
testcase_19	AC	657 ms; 44,124 KB
testcase_20	AC	603 ms; 44,124 KB
testcase_21	AC	672 ms; 46,172 KB
testcase_22	AC	576 ms; 44,124 KB
testcase_23	AC	586 ms; 44,124 KB
testcase_24	AC	571 ms; 44,124 KB
testcase_25	AC	656 ms; 46,172 KB
testcase_26	AC	629 ms; 46,172 KB
testcase_27	AC	674 ms; 46,172 KB
testcase_28	AC	584 ms; 44,124 KB
testcase_29	AC	621 ms; 46,172 KB
testcase_30	AC	625 ms; 46,172 KB
testcase_31	AC	614 ms; 44,124 KB
testcase_32	AC	565 ms; 44,124 KB
testcase_33	AC	655 ms; 46,172 KB
testcase_34	AC	558 ms; 44,124 KB
testcase_35	AC	550 ms; 37,336 KB
testcase_36	AC	531 ms; 37,456 KB
testcase_37	AC	625 ms; 46,172 KB
testcase_38	AC	582 ms; 44,124 KB
testcase_39	AC	648 ms; 46,172 KB
testcase_40	AC	617 ms; 46,172 KB
testcase_41	AC	605 ms; 44,124 KB
testcase_42	AC	570 ms; 44,124 KB
testcase_43	AC	647 ms; 46,172 KB
testcase_44	AC	618 ms; 46,172 KB
testcase_45	AC	660 ms; 46,172 KB
testcase_46	AC	583 ms; 46,172 KB
testcase_47	AC	658 ms; 46,172 KB
testcase_48	AC	592 ms; 44,124 KB
testcase_49	AC	611 ms; 46,172 KB

ソースコード

#include <bits/stdc++.h>
// clang-format off
using namespace std; using ll=long long; using ull=unsigned long long; using pll=pair<ll,ll>; const ll INF=4e18;
#define debug1(a) { cerr<<#a<<":"<<a<<endl; }
#define debug2(a,b) { cerr<<#a<<":"<<a<<" "<<#b<<":"<<b<<endl; }
#define debug3(a,b,c) { cerr<<#a<<":"<<a<<" "<<#b<<":"<<b<<" "<<#c<<":"<<c<<endl; }
#define debug4(a,b,c,d) { cerr<<#a<<":"<<a<<" "<<#b<<":"<<b<<" "<<#c<<":"<<c<<" "<<#d<<":"<<d<<endl; }

struct card_t { ll a; ll b; };
bool operator==(const card_t &lhs, const card_t &rhs) { return (lhs.a == rhs.a && lhs.b == rhs.b); }
bool operator!=(const card_t &lhs, const card_t &rhs) { return !(lhs == rhs); }
bool operator<(const card_t &lhs, const card_t &rhs) {
    if (lhs.a != rhs.a){return lhs.a<rhs.a;}
    return lhs.b<rhs.b;
}
card_t avg(card_t x, card_t y){
    return card_t{(x.a+y.a)/2,(x.b+y.b)/2};
}
std::ostream &operator<<(std::ostream &os, card_t &pt) {
    string s;
    s = "(" + to_string(ll(pt.a)) + ", " + to_string(ll(pt.b)) + ")";
    return os << s;
};
// clang-format on

namespace marathon {
mt19937 engine(0);
clock_t start_time;
double now() {
    return 1000.0 * (clock() - start_time) / CLOCKS_PER_SEC;
}
void marathon_init() {
    start_time = clock();
    random_device seed_gen;
    engine.seed(seed_gen());
}
int randint(int mn, int mx) {
    int rng = mx - mn + 1;
    return mn + (engine() % rng);
}
double uniform(double x, double y) {
    const int RND = 1e8;
    double mean = (x + y) / 2.0;
    double dif = y - mean;
    double p = double(engine() % RND) / RND;
    return mean + dif * (1.0 - 2.0 * p);
}
template <typename T>
T random_choice(vector<T> &vec) {
    return vec[engine() % vec.size()];
}
bool anneal_accept(double new_score, double old_score, double cur_time, double begin_time, double end_time, double begin_temp, double end_temp) {
    const int ANNEAL_RND = 1e8;
    const double ANNEAL_EPS = 1e-6;
    double temp = (begin_temp * (end_time - cur_time) + end_temp * (cur_time - begin_time)) / (end_time - begin_time);
    return (exp((new_score - old_score) / temp) > double(engine() % ANNEAL_RND) / ANNEAL_RND + ANNEAL_EPS);
}
}  // namespace marathon
const int OPLIMIT = 50;
const int N = 45;
const ll F17 = 500000000000000000;
card_t INIT_AB[N];
double evaluate(card_t x) {
    double da = abs(x.a - F17);
    double db = abs(x.b - F17);
    return max(da, db) * 100 + min(da, db);
}
double evaluate2(card_t x, card_t dest) {
    double da = abs(x.a - dest.a);
    double db = abs(x.b - dest.b);
    return max(da, db) * 100 + min(da, db);
}
void rec(vector<int> &ops, vector<bool> &used, pair<double, vector<int>> &best_result, card_t used_total, card_t target, int lastind, int maxops, vector<card_t> &now_cards) {
    if (ops.size() >= 1) {
        auto new_zero = avg(used_total, now_cards[lastind]);
        double e = evaluate(new_zero);
        if (e < best_result.first) {
            best_result = {e, ops};
        }
    }
    if (ops.size() >= maxops) {
        return;
    }
    for (int j = 0; j < N; j++) {
        if (used[j]) continue;
        used[j] = true;
        ops.push_back(j);
        card_t nxt_used_total = (used_total.a <= 0) ? now_cards[j] : avg(now_cards[j], used_total);
        rec(ops, used, best_result, nxt_used_total, target, lastind, maxops, now_cards);
        ops.pop_back();
        used[j] = false;
    }
}
void do_op(int i, int j, vector<card_t> &now_cards, vector<pair<int, int>> &result) {
    card_t avg_ = avg(now_cards[i], now_cards[j]);
    now_cards[i] = avg_;
    now_cards[j] = avg_;
    result.push_back({i, j});
}
void output(vector<pair<int, int>> &result) {
    cout << result.size() << endl;
    for (auto p : result) {
        cout << p.first + 1 << " " << p.second + 1 << endl;
    }
}

struct state_t {
    int id;
    bitset<N> used;
    ll a;
    ll b;
    double score;
    double realscore;
};
uint8_t stateid_to_cardid[10000000];
int stateid_to_preid[10000000];
int stateid_size = 0;
void add_state(state_t &pre, state_t &nxt, uint8_t card_id) {
    nxt.id = stateid_size;
    stateid_to_cardid[stateid_size] = card_id;
    stateid_to_preid[stateid_size] = pre.id;
    stateid_size++;
}
bool operator<(const state_t &lhs, const state_t &rhs) {
    return lhs.score < rhs.score;
}
void beam_swap(vector<state_t> &stats, vector<state_t> &nstats, int beamsize) {
    int nst_num = nstats.size();
    vector<int> perm(nst_num);
    iota(perm.begin(), perm.end(), 0);
    sort(perm.begin(), perm.end(), [&](int a, int b) {
        return nstats[a].score > nstats[b].score;
    });
    unordered_set<ull> hashes;
    stats.clear();
    for (int i = 0; i < nst_num; i++) {
        auto nst = nstats[perm[i]];

        stats.push_back(nst);
        if (int(stats.size()) >= beamsize) {
            break;
        }
    }
}
vector<int> beamsearch(int opnum, vector<card_t> &now_cards) {
    state_t init_state;
    {
        init_state.used = 0;
        init_state.used[0] = 1;
        init_state.id = 0;
        stateid_size = 1;
        init_state.a = now_cards[0].a / 2;
        init_state.b = now_cards[0].b / 2;
        init_state.score = -1e18;
        init_state.realscore = -1e18;
    }
    state_t beststate = init_state;
    int beamwidth = 4000;
    vector<state_t> stats = {init_state};
    auto card0 = now_cards[0];
    for (int op = 1; op <= opnum; op++) {
        debug3(op, stats.size(),stateid_size);
        vector<state_t> nstats;
        for (auto state : stats) {
            for (int card_id = 1; card_id < N; card_id++) {
                if (state.used[card_id]) continue;
                auto nst = state;
                ll da = now_cards[card_id].a / (2ll << op);
                ll db = now_cards[card_id].b / (2ll << op);
                nst.a += da;
                nst.b += db;

                ll df = F17 / (2ll << op);
                nst.score = -evaluate({nst.a + df, nst.b + df});
                nst.realscore = -evaluate({nst.a + da, nst.b + db});
                nst.used[card_id] = true;
                add_state(state, nst, card_id);

                if (beststate.realscore < nst.realscore) {
                    beststate = nst;
                }
                if (nst.a > F17 + 100000) continue;
                if (nst.b > F17 + 100000) continue;
                nstats.push_back(nst);
            }
        }
        debug2(stats.size(), nstats.size());
        beam_swap(stats, nstats, beamwidth);
    }
    {
        vector<int> ops;
        int state_id = beststate.id;
        while (state_id > 0) {
            ops.push_back(stateid_to_cardid[state_id]);
            state_id = stateid_to_preid[state_id];
        }
        reverse(ops.begin(), ops.end());
        return ops;
    }
}
void solve() {
    vector<card_t> now_cards(N);
    for (int i = 0; i < N; i++) {
        now_cards[i] = INIT_AB[i];
    }
    vector<pair<int, int>> result;
    int it = 0;
    {
        card_t init_0 = now_cards[0];
        vector<int> ops;
        vector<bool> used(N);
        pair<double, vector<int>> best_result = {evaluate(now_cards[0]) * 0.999, {}};
        int maxop = min(4, OPLIMIT - 1 - int(result.size()));
        auto work_cards = now_cards;
        rec(ops, used, best_result, {0, 0}, init_0, 0, maxop, work_cards);
        for (int j = 0; j < int(best_result.second.size()) - 1; j++) {
            do_op(best_result.second[j], best_result.second[j + 1], now_cards, result);
        }
        do_op(best_result.second.back(), 0, now_cards, result);
    }
    debug2(evaluate(now_cards[0]), now_cards[0]);
    {
        auto ops = beamsearch(44, now_cards);
        int m = ops.size();
        if (m > 0) {
            for (int i = m - 1; i >= 1; i--) {
                do_op(ops[i], ops[i - 1], now_cards, result);
            }
            do_op(0, ops[0], now_cards, result);
        }
    }
    debug2(evaluate(now_cards[0]), now_cards[0]);
    debug1(marathon::now());
    output(result);
}
int main() {
    marathon::marathon_init();
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        ll a, b;
        cin >> a >> b;
        INIT_AB[i] = card_t{a, b};
    }
    solve();
    return 0;
}