Submission #647985

#	Time	Username	Problem	Language	Result	Execution time	Memory
647985		mychecksedad	Political Development (BOI17_politicaldevelopment)	C++17	100 / 100	282 ms	379708 KiB

politicaldevelopment

/* Author : Mychecksdead */
#include<bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long int ll;
typedef long double ld;
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define PI 3.1415926535
#define pb push_back
#define setp() cout << setprecision(15)
#define all(x) x.begin(), x.end()
#define oset tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
#define debug(x) cerr << #x << " is " << x << '\n';
const int N = 1e6+100, M = 1e5+10, F = 2147483646, K = 20, MO = 99000007;


int n, k;
vector<int> g[N], path, r[N];
vector<bool> vis(N);
vector<bitset<50005>> is;
ll e[N];
void dfs(int v, int p){
    vis[v] = 1;
    path.pb(v);
    for(int u: g[v]){
        if(u != p){
            if(vis[u]){
                if(path[path.size() - 3] == u){
                    cout << 3;
                    exit(0);
                }
            }else{
                dfs(u, v);
            }
        }    
    }
    path.pop_back();
}

int mod(ll a){
    return ((a%MO)+MO)%MO;
}
vector<vector<int>> v;

void solve(){
    cin >> n >> k;
    is.resize(n+1);
    for(int i = 0; i < n; ++i){
        int d; cin >> d; 
        for(int j = 0; j < d; ++j){
            int x; cin >> x; g[i].pb(x); is[i][x] = 1;
            if(x > i) r[i].pb(x);
        }
    }
    if(k <= 2){
        for(int i = 0; i < n; ++i){
            if(g[i].size()){
                cout << 2;
                return;
            }
        }
        cout << 1;
        return;
    }
    if(k <= 3){
        for(int i = 0; i < n; ++i) if(!vis[i]) dfs(i, i);
        for(int i = 0; i < n; ++i){
            if(g[i].size()){
                cout << 2;
                return;
            }
        }
        cout << 1;
        return;
    }

    e[0] = 1;
    for(int i = 1; i < N; ++i) e[i] = (e[i - 1] * 5) % MO;

    bool o = 0;
    for(int i = 0; i < n; ++i) if(g[i].size() > 0) o = 1;
    if(!o){
        cout << 1;
        return;
    }

    bitset<50005> bb;
    for(int i = 0; i < n; ++i){
        for(int u: r[i]){
            int x = i, y = u;
            if(r[x].size() > r[y].size()) swap(x, y);
            for(int p: r[x]){
                if(p != y && is[p][y]){
                    v.pb(vector<int> {x, y, p});
                }
            }
        }
    }

    if(v.size() == 0){
        cout << 2;
        return;
    }

    for(int j = 4; j <= k; ++j){
        bitset<50005> out, in;
        vector<vector<int>> t;
        bitset<N*100> m;

        for(auto &u: v){
            ll h = 0;
            for(int x: u) in[x] = 1, h += e[x];
            h = mod(h);
            vector<int> extend;
            for(int x: u){
                for(int e: g[x]){
                    if(!out[e] && !in[e]){
                        out[e] = 1;
                        extend.pb(e);
                    }
                }
            }
            for(int x: extend){
                out[x] = 0;
                bool ok = 1;
                for(int p: u){
                    if(!is[p][x]){
                        ok = 0;
                        break;
                    }
                }
                if(ok){
                    h = mod(h + e[x]);
                    if(!m[h]){
                        m[h] = 1;
                        u.pb(x);
                        t.pb(u);
                        u.pop_back();
                    }
                    h = mod(h - e[x]);
                }
            }
            for(int x: u) in[x] = 0;
        }
        if(t.size() == 0){
            cout << j - 1;
            return;
        }
        v = t;
    }
    cout << k;
}   





int main(){
    cin.tie(0); ios::sync_with_stdio(0);
    int T = 1, aa;
    // cin >> T;aa=T;
    while(T--){
        // cout << "Case #" << aa-T << ": ";
        solve();
        cout << '\n';
    }
    return 0;
 
}

Compilation message (stderr)

politicaldevelopment.cpp: In function 'int main()':
politicaldevelopment.cpp:162:16: warning: unused variable 'aa' [-Wunused-variable]
  162 |     int T = 1, aa;
      |                ^~

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 38 / 38
• Subtask 5: 23 / 23