Submission #1234878

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234878		CrabCNH	Bitaro’s Party (JOI18_bitaro)	C++20	0 / 100	7 ms	10568 KiB

bitaro

#include <bits/stdc++.h>

#define task     "BriantheCrab"

#define int    long long
#define pii    pair <int, int>
#define fi     first
#define se     second
#define szf    sizeof
#define sz(s)  (int)((s).size())
#define all(v) (v).begin(), (v).end()

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

using namespace std;

template <class T> void minimize (T &t, T f) {if (t > f) t = f;}
template <class T> void maximize (T &t, T f) {if (t < f) t = f;}

const int maxN = 2e5 + 5;
const int inf = 1e18 + 7;
const int mod = 1e9 + 7;

int n, m, q;
vector <int> adj[maxN];
vector <pii> best[maxN];
int dist[maxN], mark[maxN], del[maxN];
int cnt = 0;
const int block = 320;

bool cmp (pii a, pii b) {
    return a.fi > b.fi;
}

void solve () {
    cin >> n >> m >> q;
    for (int i = 1; i <= m; ++ i) {
        int u, v;
        cin >> u >> v;
        adj[v].push_back (u);
    }
    for (int u = 1; u <= n; ++ u) {
        ++ cnt;
        vector <int> temp;
        dist[u] = 0;
        best[u].push_back ({0, u});
        mark[u] = cnt;
        temp.push_back (u);

        for (int v : adj[u]) {
            for (auto [d, p] : best[v]) {
                if (mark[p] != cnt) {
                    mark[p] = cnt;
                    dist[p] = d + 1;
                    best[u].push_back ({dist[p], p});
                    temp.push_back (p);
                } else {
                    maximize (dist[p], d + 1);
                }
            }
        }

        best[u].clear ();
        for (int p : temp) {
            best[u].push_back ({dist[p], p});
        }

        sort (all (best[u]), cmp);
        while (sz (best[u]) > block) {
            best[u].pop_back ();
        }
    }

    while (q --) {
        int t, y;
        cin >> t >> y;
        vector <int> banned (y);
        for (int i = 0; i < y; ++ i) {
            cin >> banned[i];
            del[banned[i]] = 1;
        }

        int res = -1;

        if (y < block - 10) {
            for (auto [d, v] : best[t]) {
                if (!del[v]) {
                    res = d;
                    break;
                }
            }
        } else {
            vector <int> dp (n + 1, 0);
            for (int i = 1; i <= n; ++ i) {
                if (del[i]) {
                    dp[i] = -inf;
                }
            }
            if (!del[t]) {
                res = 0;
            }

            for (int u = 1; u <= t; ++ u) {
                for (int v : adj[u]) {
                    if (dp[v] != -inf) {
                        maximize (dp[u], dp[v] + 1);
                    }
                }
                if (!del[u]) {
                    maximize (res, dp[u]);
                }
            }
        }

        cout << res << '\n';

        for (int v : banned) {
            del[v] = 0;
        }
    }
    return;
}

signed main () {
    cin.tie (nullptr) -> sync_with_stdio (false);
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }
    int t = 1;
    //cin >> t;
    while (t --) {
        solve ();
    } 
    return 0;
}
// thfv

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:129:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  129 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:130:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  130 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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