結果

問題 No.5007 Steiner Space Travel
ユーザー shibh308shibh308
提出日時 2022-07-30 14:08:49
言語 C++17(gcc12)
(gcc 12.3.0 + boost 1.87.0)
結果
AC  
実行時間 222 ms / 1,000 ms
コード長 6,255 bytes
コンパイル時間 3,194 ms
実行使用メモリ 3,900 KB
スコア 4,772,571
最終ジャッジ日時 2022-07-30 14:09:00
合計ジャッジ時間 10,039 ms
ジャッジサーバーID
（参考情報） 		judge11 / judge12
純コード判定しない問題か言語
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
other AC * 30
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include <bits/stdc++.h>
// #include "atcoder/all"

using namespace std;

using i64 = long long;

const i64 MOD = 1e9 + 7;
const i64 INF = i64(1e18);

template <typename T>
bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

template <typename T>
bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}


uint32_t rnd(){
    static uint32_t x = 123456789, y = 362436069, z = 521288629, w = 0;
    uint32_t t = x ^ (x << 11);
    x = y;
    y = z;
    z = w;
    w = (w ^ (w >> 19)) ^ (t ^ (t >> 8));
    return w;
}

double rnd_double(){
    return 1.0 * rnd() / numeric_limits<uint32_t>::max();
}

// #define OPTIMIZE

namespace params{
void load_params(){
    ifstream ifs("../params.txt");
    assert(ifs.is_open());
}
}


// doc: https://shibh308.github.io/library/library/lib/functions/tsp.cpp.html
template<typename T>
vector<int> tsp(int n, vector<vector<T>> dist){
    // 始点=終点のTSP n <= 2 とかでバグりそうなので注意
    vector<int> v(n);
    vector<int> inv(n);
    // 適当に初期解を生成
    iota(v.begin(), v.end(), 0);
    T now_dist = 0;
    for(int i = 0; i < n; ++i){
        inv[v[i]] = i;
        now_dist += dist[v[i]][v[(i + 1) % n]];
    }
    // 前計算
    vector<vector<pair<T,int>>> near_vertexes(n);
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < n; ++j){
            near_vertexes[i].emplace_back(dist[i][j], j);
        }
        sort(near_vertexes[i].begin(), near_vertexes[i].end());
    }

    auto dist_check = [&](){
        auto di = dist[0][0];
        for(int i = 0; i < n; ++i){
            di += dist[v[i]][v[(i + 1) % n]];
        }
        assert(abs(now_dist - di) <= 1e-6);
    };

    auto update = [&](int i1, int i3){
        int i2 = (i1 + 1) % n;
        int i4 = (i3 + 1) % n;

        if(i1 == i3 || i2 == i3 || i1 == i4 || i2 == i4)
            return false;
        if(dist[v[i1]][v[i2]] + dist[v[i3]][v[i4]] <= dist[v[i1]][v[i3]] + dist[v[i2]][v[i4]])
            return false;

        auto improve = (dist[v[i1]][v[i2]] + dist[v[i3]][v[i4]]) - (dist[v[i1]][v[i3]] + dist[v[i2]][v[i4]]);
        now_dist -= improve;

        int d1 = (i2 < i3 ? i3 - i2 : i3 + n - i2);
        int d2 = (i4 < i1 ? i1 - i4 : i1 + n - i4);
        if(d1 >= d2){
            swap(i1, i3);
            swap(i2, i4);
        }

        int st = i2;
        int en = i2 < i3 ? i3 : i3 + n;
        while(st < en){
            inv[v[en % n]] = st % n;
            inv[v[st % n]] = en % n;
            swap(v[st % n], v[en % n]);
            ++st, --en;
        }
        // バグが怖い時用
        // dist_check();

        return true;
    };

    auto neighbors_search = [&](){
        for(int i = 0; i < n; ++i){
            int idx1 = i;
            int idx2 = (i + 1) % n;
            int v1 = v[idx1];
            int v2 = v[idx2];
            for(auto [d, v3] : near_vertexes[v1]){
                if(v3 == v2)
                    break;
                int idx3 = inv[v3];
                if(update(idx1, idx3)){
                    return true;
                }
            }
            for(auto [d, v4] : near_vertexes[v2]){
                if(v4 == v1)
                    break;
                int idx3 = (inv[v4] + n - 1) % n;
                if(update(idx1, idx3)){
                    return true;
                }
            }
        }
        return false;
    };
    auto double_bridge = [&](){
        vector<uint32_t> r{rnd() % n, rnd() % n, rnd() % n, rnd() % n};
        sort(r.begin(), r.end());
        if(r[0] == r[1] || r[1] == r[2] || r[2] == r[3]){
            return true;
        }
        // (r[3] + 1, r[0]) => (r[2] + 1, r[3]) => (r[1] + 1, r[2]) => (r[0] + 1, r[1])

        auto diff = dist[0][0];
        diff -= dist[v[r[0]]][v[r[0] + 1]];
        diff -= dist[v[r[1]]][v[r[1] + 1]];
        diff -= dist[v[r[2]]][v[r[2] + 1]];
        diff -= dist[v[r[3]]][v[(r[3] + 1) % n]];
        diff += dist[v[r[0]]][v[r[2] + 1]];
        diff += dist[v[r[3]]][v[r[1] + 1]];
        diff += dist[v[r[2]]][v[r[0] + 1]];
        diff += dist[v[r[1]]][v[(r[3] + 1) % n]];
        now_dist += diff;
        vector<int> nex;
        nex.reserve(n);
        for(int i = r[3] + 1; i < n; ++i)
            nex.emplace_back(v[i]);
        for(int i = 0; i <= r[0]; ++i)
            nex.emplace_back(v[i]);
        for(int i = r[2] + 1; i <= r[3]; ++i)
            nex.emplace_back(v[i]);
        for(int i = r[1] + 1; i <= r[2]; ++i)
            nex.emplace_back(v[i]);
        for(int i = r[0] + 1; i <= r[1]; ++i)
            nex.emplace_back(v[i]);
        v = move(nex);
        return false;
    };

    auto best = make_pair(now_dist, v);
    for(int i = 0; i < 1000; ++i){
        if(i){
            while(double_bridge());
        }
        while(neighbors_search());
        if(!chmin(best, make_pair(now_dist, v))){
            tie(now_dist, v) = best;
        }
    }
    for(int i = 0; i < n; ++i){
        if(v[i] == 0){
            vector<int> res;
            for(int j = 0; j < n; ++j){
                res.emplace_back(v[(i + j) % n]);
            }
            return res;
        }
    }
    // return now_dist;
    return v;
}


constexpr int n = 100;
constexpr int m = 8;
constexpr int alpha = 5;
array<int, n> ax, ay;

void read_file(istream& ifs){
    int a;
    ifs >> a >> a;
    // TODO: input
    for(int i = 0; i < n; ++i){
        ifs >> ax[i] >> ay[i];
    }
}

clock_t st;

void solve(){
    vector<vector<i64>> dist(n, vector<i64>(n));
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < n; ++j){
            dist[i][j] = (ax[i] - ax[j]) * (ax[i] - ax[j]) + (ay[i] - ay[j]) * (ay[i] - ay[j]) * 25;
        }
    }
    auto res = tsp(100, dist);

    for(int i = 0; i < m; ++i){
        cout << 0 << " " << 0 << endl;
    }
    cout << res.size() + 1 << endl;
    for(int i = 0; i < n; ++i){
        cout << 1 << " " << res[i] + 1 << endl;
    }
    cout << 1 << " " << 1 << endl;
}

signed main(){

    st = clock();

#ifdef OPTIMIZE
    params::load_params();
#endif

#ifndef HAND
    read_file(cin);
#else
    ifstream ifs("./tools/in/0000.txt");
    assert(ifs.is_open());
    read_file(ifs);
#endif

    solve();

}
0