oj.uz

Submission #921873

# Submission time Handle Problem Language Result Execution time Memory
921873 2024-02-04T12:38:33 Z boris_mihov Meetings (JOI19_meetings) C++17
100 / 100
 811 ms 1412 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];
bool alreadyAdded[MAXN];
std::vector <int> g[MAXN];
std::vector <int> c[MAXN];
std::vector <int> real[MAXN];
std::mt19937 rng(69420);
 
void removeEdge(int u, int v)
{
    if (u == -1 || v == -1)
    {
        return;
    }
    
    for (int &x : g[u])
    {
        if (x == v)
        {
            std::swap(x, g[u].back());
            g[u].pop_back();
            break;
        }
    }
 
    for (int &x : g[v])
    {
        if (x == u)
        {
            std::swap(x, g[v].back());
            g[v].pop_back();
            break;
        }
    }
}
 
void addEdge(int u, int v)
{
    if (u == -1 || v == -1)
    {
        return;
    }
 
    g[u].push_back(v);
    g[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 added)
{
    bool addedEdge = false;
    for (int i = 0 ; i < c[node].size() ; i += 2)
    {
        if (i == c[node].size() - 1)
        {
            int res = Query(node, real[node][i], added);
            if (res == node)
            {
                continue;
            }

            if (res != node && res != real[node][i] && res != added)
            {
                removeEdge(node, real[node][i]);
                addEdge(node, res);
                addEdge(res, real[node][i]);
                addEdge(res, added);
                alreadyAdded[res] = true;
                return;
            }
    
            if (res == added)
            {
                removeEdge(node, real[node][i]);
                if (!addedEdge) 
                {
                    addEdge(node, added);
                    addedEdge = true;
                }
    
                addEdge(real[node][i], added);
                continue;
            }
    
            if (res == real[node][i])
            {
                search(c[node][i], added);
                return;
            }

            assert(false);
        }

        int res = Query(real[node][i], real[node][i + 1], added);
        // std::cout << "res is: " << real[node][i] << ' ' << real[node][i + 1] << ' ' << added << " = " << res << '\n';
        if (res == node)
        {
            continue;
        }

        if (res == added)
        {
            int res2 = Query(node, real[node][i], added);
            if (res == res2)
            {
                removeEdge(node, real[node][i]);
                if (!addedEdge) 
                {
                    addEdge(node, added);
                    addedEdge = true;
                }
    
                addEdge(real[node][i], added);
            } else
            {
                removeEdge(node, real[node][i + 1]);
                if (!addedEdge) 
                {
                    addEdge(node, added);
                    addedEdge = true;
                }
    
                addEdge(real[node][i + 1], added);
            }

            return;
        }

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

        if (res == real[node][i + 1])
        {
            search(c[node][i + 1], added);
            return;
        }
    
        if (res != node && res != real[node][i] && res != added)
        {
            int res2 = Query(node, real[node][i], added);
            if (res == res2)
            {
                removeEdge(node, real[node][i]);
                addEdge(node, res);
                addEdge(res, real[node][i]);
                addEdge(res, added);
                alreadyAdded[res] = true;
            } else
            {
                removeEdge(node, real[node][i + 1]);
                addEdge(node, res);
                addEdge(res, real[node][i + 1]);
                addEdge(res, added);
                alreadyAdded[res] = true;
            }
            return;
        
        }

        assert(false);
    }
 
    if (!addedEdge)
    {
        addEdge(node, added);
    }
}
 
void Solve(int N) 
{
    n = N;
    std::iota(perm, perm + n, 0);
    std::shuffle(perm, perm + n, rng);

    for (int i = 0 ; i < n ; ++i)
    {
        g[i].clear();
        c[i].clear();
        real[i].clear();
    }
 
    g[perm[0]].push_back(perm[1]);
    g[perm[1]].push_back(perm[0]);
 
    // std::cout << "edge: " << perm[0] << ' ' << perm[1] << '\n';
    for (int i = 2 ; i < n ; ++i)
    {
        // std::cout << "current: " << perm[i] << '\n';
        if (alreadyAdded[perm[i]])
        {
            continue;
        }

        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]);        
        search(root, perm[i]);
    }
    
    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)':
meetings.cpp:113:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |     for (int i = 0 ; i < c[node].size() ; i += 2)
      |                      ~~^~~~~~~~~~~~~~~~
meetings.cpp:115:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  115 |         if (i == c[node].size() - 1)
      |             ~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 600 KB Output is correct
2 Correct 0 ms 596 KB Output is correct
3 Correct 1 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 1 ms 600 KB Output is correct
7 Correct 1 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 1 ms 600 KB Output is correct
12 Correct 0 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 0 ms 596 KB Output is correct
3 Correct 1 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 1 ms 600 KB Output is correct
7 Correct 1 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 1 ms 600 KB Output is correct
12 Correct 0 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 852 KB Output is correct
18 Correct 1 ms 600 KB Output is correct
19 Correct 1 ms 600 KB Output is correct
20 Correct 1 ms 600 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 0 ms 596 KB Output is correct
3 Correct 1 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 1 ms 600 KB Output is correct
7 Correct 1 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 1 ms 600 KB Output is correct
12 Correct 0 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 852 KB Output is correct
18 Correct 1 ms 600 KB Output is correct
19 Correct 1 ms 600 KB Output is correct
20 Correct 1 ms 600 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 8 ms 600 KB Output is correct
28 Correct 8 ms 688 KB Output is correct
29 Correct 8 ms 600 KB Output is correct
30 Correct 9 ms 600 KB Output is correct
31 Correct 7 ms 600 KB Output is correct
32 Correct 6 ms 600 KB Output is correct
33 Correct 7 ms 600 KB Output is correct
34 Correct 8 ms 600 KB Output is correct
35 Correct 8 ms 600 KB Output is correct
36 Correct 8 ms 692 KB Output is correct
37 Correct 11 ms 708 KB Output is correct
38 Correct 11 ms 600 KB Output is correct
39 Correct 12 ms 692 KB Output is correct

Subtask #4
71.0 / 71.0

# Verdict Execution time Memory Grader output
1 Correct 554 ms 852 KB Output is correct
2 Correct 552 ms 872 KB Output is correct
3 Correct 537 ms 1064 KB Output is correct
4 Correct 537 ms 1156 KB Output is correct
5 Correct 401 ms 816 KB Output is correct
6 Correct 385 ms 884 KB Output is correct
7 Correct 419 ms 848 KB Output is correct
8 Correct 472 ms 1080 KB Output is correct
9 Correct 425 ms 900 KB Output is correct
10 Correct 453 ms 1104 KB Output is correct
11 Correct 470 ms 1368 KB Output is correct
12 Correct 610 ms 932 KB Output is correct
13 Correct 567 ms 1356 KB Output is correct
14 Correct 756 ms 1188 KB Output is correct
15 Correct 674 ms 1412 KB Output is correct
16 Correct 700 ms 940 KB Output is correct
17 Correct 464 ms 832 KB Output is correct
18 Correct 656 ms 1084 KB Output is correct
19 Correct 669 ms 848 KB Output is correct
20 Correct 738 ms 1092 KB Output is correct
21 Correct 716 ms 848 KB Output is correct
22 Correct 706 ms 848 KB Output is correct
23 Correct 733 ms 1108 KB Output is correct
24 Correct 676 ms 1088 KB Output is correct
25 Correct 717 ms 876 KB Output is correct
26 Correct 668 ms 1148 KB Output is correct
27 Correct 734 ms 1172 KB Output is correct
28 Correct 475 ms 824 KB Output is correct
29 Correct 410 ms 1344 KB Output is correct
30 Correct 465 ms 932 KB Output is correct
31 Correct 437 ms 848 KB Output is correct
32 Correct 811 ms 1224 KB Output is correct
33 Correct 701 ms 1044 KB Output is correct
34 Correct 8 ms 600 KB Output is correct
35 Correct 8 ms 852 KB Output is correct
36 Correct 8 ms 600 KB Output is correct
37 Correct 8 ms 600 KB Output is correct
38 Correct 7 ms 676 KB Output is correct
39 Correct 6 ms 600 KB Output is correct
40 Correct 7 ms 600 KB Output is correct
41 Correct 11 ms 936 KB Output is correct
42 Correct 8 ms 600 KB Output is correct
43 Correct 9 ms 600 KB Output is correct
44 Correct 13 ms 600 KB Output is correct
45 Correct 11 ms 712 KB Output is correct
46 Correct 11 ms 708 KB Output is correct
47 Correct 1 ms 600 KB Output is correct
48 Correct 1 ms 600 KB Output is correct
49 Correct 1 ms 600 KB Output is correct
50 Correct 1 ms 600 KB Output is correct
51 Correct 1 ms 600 KB Output is correct
52 Correct 1 ms 600 KB Output is correct
53 Correct 1 ms 600 KB Output is correct
54 Correct 0 ms 600 KB Output is correct
55 Correct 0 ms 600 KB Output is correct
56 Correct 1 ms 600 KB Output is correct
57 Correct 1 ms 600 KB Output is correct
58 Correct 1 ms 600 KB Output is correct
59 Correct 1 ms 600 KB Output is correct
60 Correct 1 ms 600 KB Output is correct
61 Correct 0 ms 600 KB Output is correct
62 Correct 1 ms 600 KB Output is correct
63 Correct 0 ms 600 KB Output is correct
64 Correct 0 ms 600 KB Output is correct
65 Correct 1 ms 600 KB Output is correct
66 Correct 0 ms 852 KB Output is correct
67 Correct 0 ms 600 KB Output is correct
68 Correct 0 ms 600 KB Output is correct
69 Correct 0 ms 600 KB Output is correct
70 Correct 0 ms 600 KB Output is correct
71 Correct 0 ms 600 KB Output is correct
72 Correct 0 ms 600 KB Output is correct