Submission #702459

#	Time	Username	Problem	Language	Result	Execution time	Memory
702459		PixelCat	Meetings (JOI19_meetings)	C++14	29 / 100	1924 ms	1292 KiB

meetings

#include "meetings.h"

#include <bits/stdc++.h>
#define For(i, a, b) for(int i = a; i <= b; i++)
#define Forr(i, a, b) for(int i = a; i >= b; i--)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) ((int)x.size())
#define eb emplace_back
#define int LL
using namespace std;
using LL = long long;
using pii = pair<int, int>;

const int MAXN = 2010;

// struct DSU {
//     int p[MAXN];
//     void init() {
//         memset(p, -1, sizeof(p));
//     }
//     int find(int n) {
//         if(p[n] < 0) return n;
//         return p[n] = find(p[n]);
//     }
//     void uni(int a, int b) {
//         a = find(a); b = find(b);
//         if(a != b) p[b] = a;
//     }
// } dsu;

mt19937_64 rng(48763);
vector<pii> edges;

int m_qry(int a, int b, int c) {
    if(a == b) return a;
    if(a == c) return a;
    if(b == c) return b;
    return Query(a, b, c);
}

void solve(vector<int> &ids) {
    if(sz(ids) == 1) return;
    if(sz(ids) == 2) {
        edges.eb(ids[0], ids[1]);
        // for(auto &i:ids) cout << i << " ";
        // cout << " - " << ids[0] << " " << ids[1] << "\n" << flush;
        return;
    }

    int rt = rng() % sz(ids);
    int p1 = rng() % sz(ids);
    while(p1 == rt) p1 = rng() % sz(ids);
    rt = ids[rt]; p1 = ids[p1];
    int p2 = p1;

    vector<int> a(1, p1), b(1, rt);
    for(auto &i:ids) if(i != rt && i != p1) {
        // cout << rt << " " << p2 << " " << i << "\n" << flush;
        auto res = m_qry(rt, p2, i);
        if(res != rt) {
            a.eb(i);
            p2 = res;
        } else {
            b.eb(i);
        }
    }
    // for(auto &i:ids) cout << i << " ";
    // cout << " - " << rt << " " << p2 << "\n" << flush;
    edges.eb(rt, p2);
    solve(a);
    solve(b);
}

void Solve(int32_t n) {
    edges.clear();
    vector<int> ids(n);
    For(i, 0, n - 1) ids[i] = i;
    solve(ids);
    for(auto &p:edges) {
        if(p.F > p.S) swap(p.F, p.S);
        Bridge(p.F, p.S);
    }
}
//   int x = Query(0, 1, 2);
//   for (int u = 0; u < N - 1; ++u) {
//     Bridge(u, u + 1);
//   }

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 12 / 12
• Subtask 4: 0 / 71