Submission #1234847

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234847		CrabCNH	Bitaro’s Party (JOI18_bitaro)	C++20	0 / 100	18 ms	21064 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;

// khong tu code thi khong kha len duoc dau

int n, m, q;
int a[maxN];
int L[maxN], d[maxN];
vector <int> adj[maxN], adj1[maxN];
vector <pii> best[maxN];
int visited[maxN];
int del[maxN];
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);
        adj1[u].push_back (v);
    }
    for (int u = 1; u <= n; u ++) {
        visited[u] = u;
        best[u].push_back ({0, u});
        for (auto v : adj[u]) {
            for (auto [val, p] : best[v]) {
                if (visited[p] != u) {
                    visited[p] = p;
                    L[p] = val + 1;
                    //cout << L[p] << '\n';
                    best[u].push_back ({L[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> cc;
        for (int i = 1; i <= y; i ++) {
            int x;
            cin >> x;
            cc.push_back (x);
            del[x] = 1;
        }
        if (y < block - 10) {
            int res = -1;
            for (auto [val, it] : best[t]) {
                //cout << val << '\n';
                if (del[it] == 0) {
                    res = val;
                    break;
                }
            }
            cout << res << '\n';
        }
        else {
            int res = -1;
            for (int u = 1; u <= n; u ++) {
                d[u] = 0;
                if (del[u] == 1) {
                    d[u] = -inf;
                }
            }
            if (del[t] == 0) {
                res = 0;
            }
            for (int u = 1; u <= t; u ++) {
                for (auto it : adj[u]) {
                    maximize (d[u], d[it] + 1);
                    if (del[u] == 0) {
                        //cout << it << ' ' << d[it] << '\n';
                        maximize (res, d[u]);
                    }
                }
            }
            cout << res << '\n';
        }
        for (auto it : cc) {
            del[it] = 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:120:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  120 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:121:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  121 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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