Submission #482030

#	Time	Username	Problem	Language	Result	Execution time	Memory
482030		Lam_lai_cuoc_doi	Meetings (JOI19_meetings)	C++17	100 / 100	971 ms	16668 KiB

meetings

#include <bits/stdc++.h>
#include "meetings.h"

using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;

template <class T>
void read(T &x)
{
    x = 0;
    register int c;
    while ((c = getchar()) && (c > '9' || c < '0'))
        ;
    for (; c >= '0' && c <= '9'; c = getchar())
        x = x * 10 + c - '0';
}

constexpr bool typetest = 0;
constexpr int N = 2e3 + 5;

//Ảo thật đấy
int lcam[N][N];

int LCA(int u, int v)
{
    if (u == v)
        return u;

    if (u == 0 || v == 0)
        return 0;

    if (lcam[u][v] != -1)
        return lcam[u][v];

    return (lcam[u][v] = lcam[v][u] = Query(0, u, v));
}

void Recursive(int root, vector<int> &s)
{
    if (s.size() == 1)
        return;
    if (s.size() == 2)
    {
        Bridge(min(s[0], s[1]), max(s[0], s[1]));
        return;
    }

    map<int, vector<int>> subtree;

    int u;
    do
    {
        u = s[rand() % s.size()];
    } while (u == root);

    vector<int> chain;

    for (auto i : s)
    {
        int lca = LCA(i, u);

        if (lca == i)
            chain.emplace_back(i);

        subtree[lca].emplace_back(i);
    }

    sort(chain.begin(), chain.end(), [&](const int &x, const int &y)
         { return LCA(x, y) == x; });

    for (int i = 0; i < (int)chain.size() - 1; ++i)
        Bridge(min(chain[i], chain[i + 1]), max(chain[i], chain[i + 1]));

    for (auto i : subtree)
        Recursive(i.first, i.second);
}

void Solve(int n)
{
    memset(lcam, -1, sizeof lcam);
    vector<int> s;
    for (int i = 0; i < n; ++i)
        s.emplace_back(i);
    random_shuffle(s.begin(), s.end());
    Recursive(0, s);
}

/*
void Read()
{
}

void Solve()
{
}

int32_t main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen("xor.INP", "r"))
    {
        freopen("xor.inp", "r", stdin);
        freopen("xor.out", "w", stdout);
    }
    int t(1);
    if (typetest)
        cin >> t;
    for (int _ = 1; _ <= t; ++_)
    {
        // cout << "Case #" << _ << ": ";
        Read();
        Solve();
    }
    // cerr << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
}

*/

Compilation message (stderr)

meetings.cpp: In function 'void read(T&)':
meetings.cpp:13:18: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   13 |     register int c;
      |                  ^

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