oj.uz

Submission #945160

# Submission time Handle Problem Language Result Execution time Memory
945160 2024-03-13T13:10:08 Z LucaIlie Friends (BOI17_friends) C++17
100 / 100
 290 ms 2132 KB 
#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 2500;
int n;
vector <int> adj[MAX_N];
unordered_map <int, bool> isAdj[MAX_N];
set <int> solution, group[MAX_N];
vector <int> frecv[MAX_N];
bool vis[MAX_N];

void findGroup( multiset <int> candidates, set<int> uniqueCandidates, set <int> chosen, int p, int q ) {
    if ( uniqueCandidates.size() > p + q )
        return;

    if ( candidates.size() == 0 ) {
        if ( chosen.size() > solution.size() )
            solution = chosen;
        return;
    }

    int v = *candidates.begin();
    if ( p > 0 ) {
        multiset <int> newCandidates = candidates;
        set<int> newUniqueCandidates = uniqueCandidates;
        set <int> newChosen = chosen;
        newCandidates.erase( v );
        newUniqueCandidates.erase( v );
        newChosen.insert( v );
        for ( int u: adj[v] ) {
            if ( chosen.find( u ) == chosen.end() ) {
                newCandidates.insert( u );
                newUniqueCandidates.insert( u );
            }
        }
        findGroup( newCandidates, newUniqueCandidates, newChosen, p - 1, q );
    }

    if ( q > 0 ) {
        multiset <int> newCandidates = candidates;
        set<int> newUniqueCandidates = uniqueCandidates;
        set <int> newChosen = chosen;
        newCandidates.erase( newCandidates.lower_bound( v ) );
        if ( newCandidates.find( v ) == newCandidates.end() )
            newUniqueCandidates.erase( v );
        findGroup( newCandidates, newUniqueCandidates, newChosen, p, q - 1 );
    }
}

bool verif() {
    for ( int v = 0; v < n; v++ ) {
        if ( frecv[v].size() > 1 )
            return false;
    }
    return true;
}

bool check( set <int> a, int q ) {
    for ( int v: a ) {
        for ( int u: adj[v] ) {
            if ( a.find( u ) == a.end() )
                q--;
        }
    }
    return (q >= 0);
}

int main() {
    int p, q;

    cin >> n >> p >> q;
    for ( int u = 0; u < n; u++ ) {
        int k;
        cin >> k;
        for ( int i = 0; i < k; i++ ) {
            int v;
            cin >> v;
            adj[u].push_back( v );
            isAdj[u][v] = true;
        }
    }
    for ( int u = 0; u < n; u++ ) {
        if ( adj[u].size() > p + q - 1 ) {
            cout << "detention\n";
            return 0;
        }
        for ( int v: adj[u] ) {
            if ( (isAdj[u][v] ^ isAdj[v][u]) == 1 ) {
                cout << "detention\n";
                return 0;
            }
        }
    }

    for ( int u = 0; u < n; u++ ) {
        if ( vis[u] )
            continue;

        multiset <int> candidates;
        set<int> uniqueCandidates;
        set <int> chosen;
        candidates.insert( u );
        uniqueCandidates.insert( u );
        solution.clear();
        findGroup( candidates, uniqueCandidates, chosen, p, q );
        if ( solution.size() == 0 ) {
            cout << "detention\n";
            return 0;
        }
        for ( int v: solution ) {
            vis[v] = true;
            frecv[v].push_back( u );
            group[u].insert( v );
        }
    }

    while ( !verif() ) {
        int x, y;
        for ( int v = 0; v < n; v++ ) {
            if ( frecv[v].size() > 1 ) {
                x = frecv[v][0], y = frecv[v][1];
                break;
            }
        }

        set <int> a = group[x], b = group[y];
        set <int> a1 = a, b1 = b;
        for ( int v: b1 )
            a1.erase( v );
        set <int> a2 = a, b2 = b;
        for ( int v: a2 )
            b2.erase( v );

        if ( check( a1, q ) ) {
            group[x] = a1;
            group[y] = b1;
        } else if ( check( b2, q ) ) {
            group[x] = a2;
            group[y] = b2;
        }


        for ( int v = 0; v < n; v++ )
            frecv[v].clear();
        for ( int u = 0; u < n; u++ ) {
            for ( int v: group[u] )
                frecv[v].push_back( u );
        }
    }

    int ans = 0;
    for ( int u = 0; u < n; u++ ) {
        if ( group[u].size() > 0 )
            ans++;
    }

    cout << "home\n";
    cout << ans << "\n";
    for ( int u = 0; u < n; u++ ) {
        if ( group[u].size() == 0 )
            continue;

        cout << group[u].size() << " ";
        for ( int v: group[u] )
            cout << v << " ";
        cout << "\n";
    }

    return 0;
}

Compilation message

friends.cpp: In function 'void findGroup(std::multiset<int>, std::set<int>, std::set<int>, int, int)':
friends.cpp:14:34: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   14 |     if ( uniqueCandidates.size() > p + q )
      |          ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
friends.cpp: In function 'int main()':
friends.cpp:84:28: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   84 |         if ( adj[u].size() > p + q - 1 ) {
      |              ~~~~~~~~~~~~~~^~~~~~~~~~~
friends.cpp:119:16: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
  119 |         int x, y;
      |                ^
friends.cpp:119:13: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
  119 |         int x, y;
      |             ^

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 604 KB Output is correct
2 Correct 0 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 0 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 600 KB Output is correct
8 Correct 1 ms 604 KB Output is correct

Subtask #2
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 604 KB Output is correct
2 Correct 3 ms 860 KB Output is correct
3 Correct 1 ms 860 KB Output is correct
4 Correct 1 ms 860 KB Output is correct
5 Correct 2 ms 1112 KB Output is correct
6 Correct 1 ms 860 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 3 ms 860 KB Output is correct

Subtask #3
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 604 KB Output is correct
2 Correct 3 ms 860 KB Output is correct
3 Correct 1 ms 860 KB Output is correct
4 Correct 1 ms 860 KB Output is correct
5 Correct 2 ms 1112 KB Output is correct
6 Correct 1 ms 860 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 3 ms 860 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 5 ms 1372 KB Output is correct
11 Correct 9 ms 1376 KB Output is correct
12 Correct 19 ms 1432 KB Output is correct
13 Correct 17 ms 1372 KB Output is correct
14 Correct 4 ms 1372 KB Output is correct
15 Correct 3 ms 1364 KB Output is correct
16 Correct 4 ms 1112 KB Output is correct

Subtask #4
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 604 KB Output is correct
2 Correct 0 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 0 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 600 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 3 ms 860 KB Output is correct
11 Correct 1 ms 860 KB Output is correct
12 Correct 1 ms 860 KB Output is correct
13 Correct 2 ms 1112 KB Output is correct
14 Correct 1 ms 860 KB Output is correct
15 Correct 1 ms 604 KB Output is correct
16 Correct 3 ms 860 KB Output is correct
17 Correct 1 ms 604 KB Output is correct
18 Correct 5 ms 1372 KB Output is correct
19 Correct 9 ms 1376 KB Output is correct
20 Correct 19 ms 1432 KB Output is correct
21 Correct 17 ms 1372 KB Output is correct
22 Correct 4 ms 1372 KB Output is correct
23 Correct 3 ms 1364 KB Output is correct
24 Correct 4 ms 1112 KB Output is correct
25 Correct 1 ms 604 KB Output is correct
26 Correct 56 ms 1468 KB Output is correct
27 Correct 40 ms 1636 KB Output is correct
28 Correct 50 ms 1568 KB Output is correct
29 Correct 25 ms 1116 KB Output is correct
30 Correct 50 ms 1364 KB Output is correct
31 Correct 5 ms 1372 KB Output is correct
32 Correct 3 ms 1372 KB Output is correct
33 Correct 290 ms 2132 KB Output is correct
34 Correct 59 ms 1868 KB Output is correct