oj.uz

Submission #921840

# Submission time Handle Problem Language Result Execution time Memory
921840 2024-02-04T11:29:56 Z boris_mihov Meetings (JOI19_meetings) C++17
29 / 100
 1743 ms 1164 KB 
#include "meetings.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <random>
#include <vector>

typedef long long llong;
const int MAXN = 2000 + 10;
const int INF  = 1e9;

int n;
int sz[MAXN];
bool bl[MAXN];
int perm[MAXN];
std::vector <int> g[MAXN];
std::vector <int> g2[MAXN];
std::vector <int> c[MAXN];
std::vector <int> real[MAXN];
std::mt19937 rng(69420);

void removeEdge(int u, int v)
{
    // std::cout << "remove edge: " << u << ' ' << v << '\n';
    if (u == -1 || v == -1)
    {
        return;
    }
    
    for (int &x : g2[u])
    {
        if (x == v)
        {
            std::swap(x, g2[u].back());
            g2[u].pop_back();
            break;
        }
    }

    for (int &x : g2[v])
    {
        if (x == u)
        {
            std::swap(x, g2[v].back());
            g2[v].pop_back();
            break;
        }
    }
}

void addEdge(int u, int v)
{
    // std::cout << "add edge: " << u << ' ' << v << '\n';
    if (u == -1 || v == -1)
    {
        return;
    }

    g2[u].push_back(v);
    g2[v].push_back(u);
}

void calcSize(int node, int par)
{
    sz[node] = 1;
    for (const int &u : g[node])
    {
        if (u == par || bl[u])
        {
            continue;
        }

        calcSize(u, node);
        sz[node] += sz[u];
    }
}

int findCentroid(int node, int par, int compSz)
{
    for (const int &u : g[node])
    {
        if (!bl[u] && u != par && sz[u] > compSz / 2)
        {
            return findCentroid(u, node, compSz);
        }
    }

    return node;
}

int decompose(int node)
{
    calcSize(node, -1);
    int cntr = findCentroid(node, -1, sz[node]);
    bl[cntr] = true;

    for (const int &u : g[cntr])
    {
        if (bl[u])
        {
            continue;
        }

        c[cntr].push_back(decompose(u));
        real[cntr].push_back(u);
    }

    return cntr;
}

void search(int node, int par, int added)
{
    // std::cout << "call: " << node << '\n';
    bool addedEdge = false;
    for (int i = 0 ; i < g[node].size() ; i++)
    {
        if (par == g[node][i])
        {
            continue;
        }

        // std::cout << "      query res: " << node << ' ' << g[node][i] << ' ' << added << " = " << "?" << '\n';
        int res = Query(node, g[node][i], added);
        // std::cout << "      query res: " << node << ' ' << g[node][i] << ' ' << added << " = " << res << '\n';
        if (res == node)
        {
            continue;
        }

        if (res == added)
        {
            if (!addedEdge) 
            {
                addEdge(node, added);
                addedEdge = true;
            }

            removeEdge(node, g[node][i]);
            addEdge(added, g[node][i]);
            continue;
        }

        if (res == g[node][i])
        {
            search(g[node][i], node, added);
            return;
        }
    }

    if (!addedEdge)
    {
        addEdge(node, added);
    }
}

void Solve(int N) 
{
    n = N;
    std::iota(perm, perm + n, 0);
    std::shuffle(perm, perm + n, rng);

    // std::cout << "order\n";
    // for (int i = 0 ; i < n ; ++i)
    // {
    //     std::cout << perm[i] << ' ';
    // }

    // std::cout << '\n';

    g[perm[0]].push_back(perm[1]);
    g[perm[1]].push_back(perm[0]);

    // std::cout << "first: " << perm[0] << '\n';
    // std::cout << "second: " << perm[1] << '\n';
    for (int i = 2 ; i < n ; ++i)
    {
        // std::cout << "here: " << perm[i] << '\n';
        for (int j = 0 ; j < n ; ++j)
        {
            c[j].clear();
            real[j].clear();
            std::shuffle(g[j].begin(), g[j].end(), rng);
        }

        std::fill(bl, bl + n, false);
        int root = decompose(perm[0]);        
    
        // for (int j = 0 ; j < n ; ++j)
        // {
        //     std::shuffle(c[j].begin(), c[j].end(), rng);
        // }

        for (int i = 0 ; i < n ; ++i)
        {
            g2[i].clear();
            for (const int &x : g[i])
            {
                g2[i].push_back(x);
            }
        }

        search(perm[0], -1, perm[i]);
        for (int i = 0 ; i < n ; ++i)
        {
            g[i].clear();
            for (const int &x : g2[i])
            {
                g[i].push_back(x);
            }
        }

        // std::cout << "after adding\n";
        // for (int i = 0 ; i < n ; ++i)
        // {
        //     for (const int &u : g[i])
        //     {
        //         if (i <= u)
        //         {
        //             std::cout << i << ' ' << u << '\n';
        //         }
        //     }
        // }
    }

    for (int i = 0 ; i < n ; ++i)
    {
        for (const int &u : g[i])
        {
            if (i < u)
            {
                Bridge(i, u);
            }
        }
    }
}

Compilation message

meetings.cpp: In function 'void search(int, int, int)':
meetings.cpp:116:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  116 |     for (int i = 0 ; i < g[node].size() ; i++)
      |                      ~~^~~~~~~~~~~~~~~~
meetings.cpp: In function 'void Solve(int)':
meetings.cpp:187:13: warning: unused variable 'root' [-Wunused-variable]
  187 |         int root = decompose(perm[0]);
      |             ^~~~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 600 KB Output is correct
2 Correct 1 ms 600 KB Output is correct
3 Correct 0 ms 600 KB Output is correct
4 Correct 0 ms 600 KB Output is correct
5 Correct 0 ms 600 KB Output is correct
6 Correct 0 ms 600 KB Output is correct
7 Correct 0 ms 600 KB Output is correct
8 Correct 0 ms 600 KB Output is correct
9 Correct 0 ms 600 KB Output is correct
10 Correct 0 ms 600 KB Output is correct
11 Correct 0 ms 600 KB Output is correct
12 Correct 1 ms 600 KB Output is correct
13 Correct 1 ms 600 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 600 KB Output is correct
2 Correct 1 ms 600 KB Output is correct
3 Correct 0 ms 600 KB Output is correct
4 Correct 0 ms 600 KB Output is correct
5 Correct 0 ms 600 KB Output is correct
6 Correct 0 ms 600 KB Output is correct
7 Correct 0 ms 600 KB Output is correct
8 Correct 0 ms 600 KB Output is correct
9 Correct 0 ms 600 KB Output is correct
10 Correct 0 ms 600 KB Output is correct
11 Correct 0 ms 600 KB Output is correct
12 Correct 1 ms 600 KB Output is correct
13 Correct 1 ms 600 KB Output is correct
14 Correct 1 ms 600 KB Output is correct
15 Correct 1 ms 600 KB Output is correct
16 Correct 1 ms 600 KB Output is correct
17 Correct 1 ms 600 KB Output is correct
18 Correct 1 ms 688 KB Output is correct
19 Correct 1 ms 600 KB Output is correct
20 Correct 1 ms 700 KB Output is correct
21 Correct 1 ms 600 KB Output is correct
22 Correct 1 ms 600 KB Output is correct
23 Correct 1 ms 600 KB Output is correct
24 Correct 1 ms 600 KB Output is correct
25 Correct 1 ms 600 KB Output is correct
26 Correct 1 ms 600 KB Output is correct

Subtask #3
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 600 KB Output is correct
2 Correct 1 ms 600 KB Output is correct
3 Correct 0 ms 600 KB Output is correct
4 Correct 0 ms 600 KB Output is correct
5 Correct 0 ms 600 KB Output is correct
6 Correct 0 ms 600 KB Output is correct
7 Correct 0 ms 600 KB Output is correct
8 Correct 0 ms 600 KB Output is correct
9 Correct 0 ms 600 KB Output is correct
10 Correct 0 ms 600 KB Output is correct
11 Correct 0 ms 600 KB Output is correct
12 Correct 1 ms 600 KB Output is correct
13 Correct 1 ms 600 KB Output is correct
14 Correct 1 ms 600 KB Output is correct
15 Correct 1 ms 600 KB Output is correct
16 Correct 1 ms 600 KB Output is correct
17 Correct 1 ms 600 KB Output is correct
18 Correct 1 ms 688 KB Output is correct
19 Correct 1 ms 600 KB Output is correct
20 Correct 1 ms 700 KB Output is correct
21 Correct 1 ms 600 KB Output is correct
22 Correct 1 ms 600 KB Output is correct
23 Correct 1 ms 600 KB Output is correct
24 Correct 1 ms 600 KB Output is correct
25 Correct 1 ms 600 KB Output is correct
26 Correct 1 ms 600 KB Output is correct
27 Correct 19 ms 600 KB Output is correct
28 Correct 19 ms 600 KB Output is correct
29 Correct 17 ms 600 KB Output is correct
30 Correct 19 ms 600 KB Output is correct
31 Correct 14 ms 600 KB Output is correct
32 Correct 22 ms 600 KB Output is correct
33 Correct 27 ms 600 KB Output is correct
34 Correct 28 ms 600 KB Output is correct
35 Correct 29 ms 600 KB Output is correct
36 Correct 13 ms 600 KB Output is correct
37 Correct 46 ms 856 KB Output is correct
38 Correct 54 ms 600 KB Output is correct
39 Correct 43 ms 748 KB Output is correct

Subtask #4
0 / 71.0

# Verdict Execution time Memory Grader output
1 Incorrect 1743 ms 1164 KB Wrong Answer [2]
2 Halted 0 ms 0 KB -