Submission #881294

#	Time	Username	Problem	Language	Result	Execution time	Memory
881294		bobbilyking	Bitaro’s Party (JOI18_bitaro)	C++17	7 / 100	2021 ms	11064 KiB

bitaro

#pragma GCC target ("avx2")
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")

#include<bits/stdc++.h>
#include<math.h>
using namespace std;

typedef int ll;
typedef long double ld;
typedef pair<ll, ll> pl;
typedef vector<ll> vl;
#define FD(i, r, l) for(ll i = r; i > (l); --i)

#define K first
#define V second
#define G(x) ll x; cin >> x;
#define GD(x) ld x; cin >> x;
#define GS(s) string s; cin >> s;
#define EX(x) { cout << x << '\n'; exit(0); }
#define A(a) (a).begin(), (a).end()
#define F(i, l, r) for (ll i = l; i < (r); ++i)

#define NN 100010
#define M 1000000007 // 998244353

vector<ll> adj[NN];
ll n;
vector<ll> topo;

bool bad[NN];
ll dpfast[NN];
constexpr ll SN = 50;

vector<pl> dp[NN]; // only keep up to sqrt(N) things in here

int main(){
//    freopen("a.in", "r", stdin);
//    freopen("a.out", "w", stdout);

    ios_base::sync_with_stdio(false); cin.tie(0);
    cout << fixed << setprecision(20);
    cin >> n; G(m) G(q)
    while (m--) {
        G(s) G(e) adj[e].push_back(s);
    } 

    {
        bool vis[NN] = {};
        vector<ll> temp;
        auto dfs = [&](auto&& self, ll i) -> void {
            if (vis[i]) return;
            vis[i] = 1;
            for (auto y: adj[i]) self(self, y);
            temp.push_back(i);
        };
        F(i, 1, n+1) if (!vis[i]) {
            temp.clear();
            dfs(dfs, i);
            topo.insert(topo.end(), temp.rbegin(), temp.rend());
        }
    }

    for (auto x: topo) {
        dp[x].emplace_back(0, x);

        for (auto y: adj[x]) {
            vector<pl> dists = std::move(dp[x]);
            dp[x].clear();
            for (auto z: dp[y]) dists.emplace_back(z.K+1, z.V);
            sort(A(dists), [](const auto &x, const auto &y) {
                if (x.V != y.V) return x.V < y.V;
                return x.K > y.K;
            });
            for (const auto &[dist, node]: dists) {
                if (!dp[x].size() || dp[x].back().V != node) {
                    dp[x].emplace_back(dist, node);
                }
            }
        }
        
    }

    while (q--) {
        G(t) G(m)
        vector<ll> v(m);
        for (auto &x: v) {
            cin >> x;
            bad[x]=1;
            dpfast[x] = -n;
        }

        if (m >= SN) {
            for (auto x: topo) {
                for (auto y: adj[x]) dpfast[x] = max(dpfast[x], 1 + dpfast[y]);
            }
            cout << (dpfast[t] < 0 ? -1: dpfast[t]) << '\n';
        } else {
            ll ans = -1;
            for (auto [dist, node]: dp[t]) if (!bad[node]) ans = max(ans, dist);
            cout << ans << '\n';
        }
        for (auto x: v) {
            bad[x] = 0;
            dpfast[x] = 0;
        }
    }
    
}

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