Submission #963200

#	Time	Username	Problem	Language	Result	Execution time	Memory
963200		TimAni	Bitaro’s Party (JOI18_bitaro)	C++17	0 / 100	1 ms	1116 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);
    };
    dfs(0, dfs);
    reverse(topo.begin(), topo.end());
    for(auto el : vis){
        assert(el);
    }
    
    vector<multiset<array<ll, 2>>> dp(n);
    for(auto el : topo){
        dp[el].insert({0, el});
    }
    
    const ll w = round(sqrt(100'000));
    for(auto u : topo){
        for(auto v : gR[u]){
            for(auto [v, i] : dp[v]){
                dp[u].insert({v + 1, i});
                if(dp[u].size() > w){
                    dp[u].erase(dp[u].begin());
                }
            }
        }
    }

    for(ll i = 0; i < q; i++){
        ll u, num;
        cin >> u >> num;
        u--;
        multiset<array<ll, 2>> ms = dp[u];
        vector<ll> c(100'000 + 1);
        for(ll j = 0; j < num; j++){
            ll a; cin >> a;
            c[--a] = 1;
        }

        ll ans = -1;
        bool been = false;
        for(auto [v, i] : ms){
            if(!c[i]){
                ans = max(ans, v);
            }
        }
        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:66:14: warning: unused variable 'been' [-Wunused-variable]
   66 |         bool been = false;
      |              ^~~~

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