Submission #1256686

#	Time	Username	Problem	Language	Result	Execution time	Memory
1256686		goulthen	Bitaro’s Party (JOI18_bitaro)	C++20	100 / 100	839 ms	277932 KiB

bitaro

//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T>
using Tree =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
#define int long long
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
#define rep(i, a, b) for (int i = a; i <= b; ++i)
#define per(i, b, a) for (int i = b; i >= a; --i)
#define pb push_back
#define eb emplace_back
#define all(v) (v).begin(), (v).end()
#define lsb(x) (x)&(-x)
#define bug(x) cerr << #x << " " << x << endl;
 
void setIO(string name = "") {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    if (!name.empty()) {
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
}
 
ll fexp(ll a, ll b, ll m) {
    if (b == 0) return 1LL;
    ll p = a;
    ll ans = 1;
    while (b > 0) {
        if (b % 2 != 0) ans = (ans * p) % m;
        p = (p * p) % m;
        b >>= 1;
    }
    return ans;
}
 
const int MAXN = 2e6 + 10;
const int INF = 1e18 + 5;
const int MOD = 1e9+7;
const int SQ = 100;

void solve() {
    int n, m, q;
    if (!(cin >> n >> m >> q)) return;
    vector<vector<int>> rg(n);
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        --u; --v;
        rg[v].pb(u);
    }

    vector<vector<pair<int,int>>> ps(n);
    vector<int> fromv(n, -1);

    for (int i = 0; i < n; i++) {
        ps[i].clear();
        ps[i].pb({0, i});
        vector<int> from_indices;

        for (int j : rg[i]) {
            for (auto &pr : ps[j]) {
                int dist = pr.fi;
                int idx = pr.se;
                if (fromv[idx] == -1) {
                    from_indices.pb(idx);
                    fromv[idx] = dist + 1;
                } else {
                    fromv[idx] = max(fromv[idx], dist + 1);
                }
            }
        }

        for (int j : from_indices) {
            ps[i].pb({fromv[j], j});
        }
        sort(ps[i].rbegin(), ps[i].rend());
        while ((int)ps[i].size() > SQ) ps[i].pop_back();

        for (int j : from_indices) fromv[j] = -1;
    }

    vector<char> mk(n, 0);
    for (int qi = 0; qi < q; qi++) {
        int t, y;
        cin >> t >> y;
        --t;
        vector<int> c(y);
        for (int i = 0; i < y; i++) {
            cin >> c[i];
            --c[i];
            mk[c[i]] = 1;
        }

        int ans = -1;
        if (y >= SQ) {
            vector<int> dp(t + 1, -1);
            dp[t] = 0;
            for (int i = t; i >= 0; --i) {
                if (dp[i] == -1) continue;
                if (!mk[i]) ans = max(ans, dp[i]);
                for (int j : rg[i]) {
                    if (j <= t) dp[j] = max(dp[j], dp[i] + 1);
                }
            }
        } else {
            for (auto &pr : ps[t]) {
                int dist = pr.fi;
                int idx = pr.se;
                if (!mk[idx]) {
                    ans = dist;
                    break;
                }
            }
        }

        cout << ans << '\n';
        for (int x : c) mk[x] = 0;
    }
}

int32_t main() {
    setIO();
    int tt = 1;
    //cin >> tt;
 
    while (tt-- > 0) solve();
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'void setIO(std::string)':
bitaro.cpp:29:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         freopen((name + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:30:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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