Submission #412591

#	Time	Username	Problem	Language	Result	Execution time	Memory
412591		ParsaAlizadeh	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	1895 ms	114424 KiB

bitaro

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;

#define X first
#define Y second

constexpr int N = 1e5 + 5;
constexpr int SQ = 100;

int mark[N], dp[N];
vector<pii> best[N];
vector<int> adj[N];

int main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    int n, m, q;
    cin >> n >> m >> q;
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        u--; v--;
        adj[v].push_back(u);
    }
    int timer = 1;
    for (int i = 0; i < n; i++) {
        vector<pii> now;
        now.emplace_back(0, i);
        for (auto &j : adj[i]) {
            for (pii const& p : best[j]) {
                now.emplace_back(p.X + 1, p.Y);
            }
        }
        sort(begin(now), end(now), greater<>());
        for (int j = 0; best[i].size() <= SQ && j < now.size(); j++) {
            if (mark[now[j].Y] == timer)
                continue;
            mark[now[j].Y] = timer;
            best[i].push_back(now[j]);
        }
        timer++;
    }
    while (q --> 0) {
        int t, cnt;
        cin >> t >> cnt;
        t--;
        for (int i = 0; i < cnt; i++) {
            int u; cin >> u; u--;
            mark[u] = timer;
        }
        if (cnt > SQ) {
            memset(dp, 0, n * sizeof(dp[0]));
            for (int i = 0; i < n; i++) {
                if (mark[i] == timer)
                    dp[i] = -1;
                for (auto &j : adj[i]) if (dp[j] != -1) {
                    dp[i] = max(dp[i], dp[j] + 1);
                }
            }
            cout << dp[t] << '\n';
        } else {
            int ans = -1;
            for (pii const& p : best[t]) {
                if (mark[p.Y] != timer) {
                    ans = p.X;
                    break;
                }
            }
            cout << ans << '\n';
        }
        timer++;
    }
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:39:51: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |         for (int j = 0; best[i].size() <= SQ && j < now.size(); j++) {
      |                                                 ~~^~~~~~~~~~~~

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