Submission #1186949

#	Time	Username	Problem	Language	Result	Execution time	Memory
1186949		steveonalex	Friends (BOI17_friends)	C++20	0 / 100	13 ms	1096 KiB

friends

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(abs(a), abs(b));}
ll lcm(ll a, ll b){return abs(a) / gcd(a, b) * abs(b);}

ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
// mt19937_64 rng(1);
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }

template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int N = 2525;
int n, p, q; 
vector<int> graph[N];
vector<vector<int>> usable;

void dfs(vector<int> v, set<vector<int>> &S){
    if (S.insert(v).second == false) return;
    vector<int> adj;
    for(int i: v)
        for(int j: graph[i]) if (!binary_search(ALL(v), j))
            adj.push_back(j);

    remove_dup(adj);

    if ((int)adj.size() <= q){
        usable.push_back(v);
        return;
    }
    if ((int)v.size() >= p) return;
    for(int i: adj){
        vector<int> _v = v;
        _v.push_back(i);
        remove_dup(_v);

        vector<int> _adj = adj;
        _adj.erase(lower_bound(ALL(_adj), i));
        for(int j: graph[i]) if (!binary_search(ALL(_v), j))
            _adj.push_back(j);

        remove_dup(_adj);

        if ((int)_v.size() + (int)_adj.size() > p + q) continue;
        dfs(_v, S);
    }
}

void solve(){
    cin >> n >> p >> q;
    for(int i = 0; i < n; ++i){
        int m; cin >> m;
        graph[i].resize(m);
        for(int &j: graph[i]) cin >> j;

        sort(ALL(graph[i]));
    }

    #define get_detention(){cout << "detention\n"; return;}

    for(int i = 0; i < n; ++i) 
        if ((int)graph[i].size() >= p + q) get_detention();

    for(int i = 0; i < n; ++i) {
        for(int j: graph[i]){
            if (!binary_search(ALL(graph[j]), i)){
                get_detention();
            }
        }
    }

    set<vector<int>> S;
    for(int i = 0; i < n; ++i){
        vector<int> v = {i};
        dfs(v, S);
    }

    vector<int> marked(n);
    vector<vector<int>> ans;
    for(auto i: usable){
        bool check = false;
        for(int j: i) if (!marked[j]){
            marked[j] = 1;
            check = true;
        }

        if (check) {
            ans.push_back(i);
        }
    }

    if (*min_element(ALL(marked)) == 0) get_detention();

    for(int i = 0; i < (int) ans.size(); ++i) for(int j = i+1; j < (int) ans.size(); ++j){
        vector<int> sigma;
        for(int x: ans[j]) if (!binary_search(ALL(ans[i]), x)) sigma.push_back(x);

        vector<int> adj;
        for(int x: sigma) for(int y: graph[x]) if (!binary_search(ALL(sigma), y)) adj.push_back(y);

        if (adj.size() <= q){
            ans[j] = sigma;
        }
        else{
            sigma.clear();
            for(int x: ans[i]) if (!binary_search(ALL(ans[j]), x)) sigma.push_back(x);
            ans[i] = sigma;
        }
    }

    cout << "home\n";
    int cnt = 0;
    for(auto i: ans) cnt += (i.size() > 0);

    cout << cnt << "\n";
    for(auto i: ans){
        if (i.size()){
            cout << i.size() << " "; printArr(i);
        }
    }
}

int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);

    clock_t start = clock();

    solve();

    cerr << "Time elapsed: " << clock() - start << "ms!\n";
    return 0;
}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 37
• Subtask 3: 0 / 12
• Subtask 4: 0 / 31