Submission #963258

#	Time	Username	Problem	Language	Result	Execution time	Memory
963258		TimAni	Bitaro’s Party (JOI18_bitaro)	C++17	7 / 100	2066 ms	32340 KiB

bitaro

//start-time: 2024-04-14 19:39:32
#include <bits/stdc++.h>

using namespace std;
using ll = long long;

void solve(){
    ll n, m, q;
    cin >> n >> m >> q;
    vector<vector<ll>> g(n);
    vector<vector<ll>> gR(n);
    for(ll i = 0; i < m; i++){
        ll u, v;
        cin >> u >> v;
        u--; v--;
        g[u].push_back(v);
        gR[v].push_back(u);
    }
    
    vector<ll> vis(n), topo;
    auto dfs = [&](ll u, auto&&dfs) -> void {
        vis[u] = 1;
        for(auto v : g[u]){
            if(!vis[v]){
                dfs(v, dfs);
            }
        }
        vis[u] = 2;
        topo.push_back(u);
    };

    for(int i = 0; i < n; i++){
        if(vis[i] == 0){
            dfs(i, dfs);
        }
    }

    reverse(topo.begin(), topo.end());
    
    vector<set<array<ll, 2>>> dp(n);
    vector<bitset<100'001>> cnt(n);
    //map<int, map<int, ll>> mp;

    for(auto el : topo){
        dp[el].insert({0, el});
        //mp[el][el] = 0;
        cnt[el][el] = 1;
    }
    
    const ll w = round(sqrt(100000)) + 1;

    for(auto u : topo){
        for(auto v : gR[u]){
            for(auto [val, i] : dp[v]){
                cnt[u] |= cnt[v];
                ll o = val + 1;
                //if(mp[u][i]) {
                    //o = max(o, mp[u][i]);
                    //dp[u].erase({mp[u][i], i});
                //}
                
                //mp[u][i] = o;
                dp[u].insert({o, i});
                if(dp[u].size() > w){
                    auto [V, I] = *dp[u].begin();
                    dp[u].erase(dp[u].begin());
                    //mp[u][I] = 0;
                }
            }
        }
    }

    for(ll i = 0; i < q; i++){
        ll u, y;
        cin >> u >> y;
        u--;
        bitset<100'001> c;
        for(ll j = 0; j < y; j++){
            ll a; cin >> a;
            c[--a] = 1;
        }

        if((cnt[u] & c) == cnt[u]){
            cout << -1 << endl;
            continue;
        }

        ll ans = 0;
        if(y < w){
            set<array<ll, 2>> ms = dp[u];
            for(auto [v, i] : ms){
                if(!c[i]){
                    ans = max(ans, v);
                }
            }
        }
        else{
            vector<int> naive(n);
            for(auto v : topo){
                naive[v] = c[v] ? -1 : 0;
                for(auto el : gR[v]){
                    naive[v] = max(naive[v], naive[el] + (naive[el] != -1));
                }
            }
            ans = naive[u];
        }
        
            //for(auto el : naive){
                //cout << el << ' ';
            //}
            //cout << endl;
        cout << ans << endl;
    }
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    ll T = 1;
    //cin >> T;
    while(T--) solve();
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'void solve()':
bitaro.cpp:65:26: warning: structured binding declaration set but not used [-Wunused-but-set-variable]
   65 |                     auto [V, I] = *dp[u].begin();
      |                          ^~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86