Submission #1234892

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234892		CrabCNH	Bitaro’s Party (JOI18_bitaro)	C++20	0 / 100	6 ms	10824 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;
int L[maxN];
int visited[maxN];
vector <int> adj[maxN];
vector <pii> best[maxN];
int curQue[maxN];
int block = 320;
int curId = 0;

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 ++) {
        best[u].clear ();
        best[u].push_back ({0, u});
        L[u] = 0;
        visited[u] = u;

        for (auto v : adj[u]) {
            for (auto [val, p] : best[v]) {
                if (visited[p] != u) {
                    visited[p] = u;
                    L[p] = val + 1;
                }
                else {
                    maximize (L[p], val + 1);
                }
            }
        }
        for (int i = 1; i <= n; i++) {
            if (visited[i] == u) {
                best[u].push_back({L[i], i});
            }
        }

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

    while (q --) {
        curId++;
        int t, y;
        cin >> t >> y;
        vector <int> cc;
        for (int i = 1; i <= y; i ++) {
            int x;
            cin >> x;
            cc.push_back (x);
            curQue[x] = curId;
        }

        if (y < block - 10) {
            int res = -1;
            for (auto [val, it] : best[t]) {
                if (curQue[it] != curId) {
                    res = val;
                    break;
                }
            }
            cout << res << '\n';
        }
        else {
            vector<int> d(n + 1);
            int res = -1;

            for (int u_dp = 1; u_dp <= n; u_dp ++) {
                if (curQue[u_dp] == curId) {
                    d[u_dp] = -inf;
                } else {
                    d[u_dp] = 0;
                }
            }

            if (curQue[t] != curId) {
                res = 0;
            }

            for (int u_dp = 1; u_dp <= n; u_dp ++) {
                if (curQue[u_dp] == curId) {
                    continue;
                }

                for (auto prd : adj[u_dp]) {
                    if (curQue[prd] != curId && d[prd] != -inf) {
                        maximize (d[u_dp], d[prd] + 1);
                    }
                }
            }
            if (curQue[t] != curId) {
                res = max(res, d[t]);
            } else {
                res = -1;
            }
            cout << res << '\n';
        }
    }
    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_cases = 1;
    while (t_cases --) {
        solve ();
    } 
    return 0;
}
// thfv

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:139:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  139 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:140:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  140 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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