Submission #1292595

#	Time	Username	Problem	Language	Result	Execution time	Memory
1292595		thaibeo123	Bitaro’s Party (JOI18_bitaro)	C++20	100 / 100	671 ms	144188 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;

#define NAME "A"
#define ll long long
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define MASK(x) (1ll << (x))
#define BIT(x, i) (((x) >> (i)) & 1)

const int N = 1e5 + 5;
const int inf = 1e9;
const int B = 100;

int n, m, q;
int val[N], dp[N];
bool block[N];
vector<int> g[N];
vector<pair<int, int>> path[N];

void input() {
    cin >> n >> m >> q;
    for (int i = 1; i <= m; i++) {
        int u, v;
        cin >> u >> v;
        g[v].pb(u);
    }
}

void solve() {
    for (int i = 1; i <= n; i++) {
        val[i] = -1;
    }
    for (int i = 1; i <= n; i++) {
        path[i].pb({0, i});
        vector<int> id;
        for (int j : g[i]) {
            for (auto it : path[j]) {
                if (val[it.se] == -1) {
                    id.pb(it.se);
                    val[it.se] = it.fi + 1;
                }
                else {
                    val[it.se] = max(val[it.se], it.fi + 1);
                }
            }
        }
        for (int x : id) {
            path[i].pb({val[x], x});
        }
        sort(all(path[i]), greater<>());
        while (path[i].size() > B) {
            path[i].pop_back();
        }
        for (int x : id) {
            val[x] = -1;
        }
    }
    while (q--) {
        int t, s;
        cin >> t >> s;
        vector<int> cur;
        for (int i = 1; i <= s; i++) {
            int x;
            cin >> x;
            block[x] = 1;
            cur.pb(x);
        }
        int ans = -1;
        if (s >= B) {
            for (int i = 1; i <= t; i++) {
                dp[i] = -inf;
            }
            dp[t] = 0;
            for (int i = t; i >= 1; i--) {
                if (block[i] == 0) {
                    ans = max(ans, dp[i]);
                }
                for (int x : g[i]) {
                    dp[x] = max(dp[x], dp[i] + 1);
                }
            }
        }
        else {
            for (auto it : path[t]) {
                if (block[it.se] == 0) {
                    ans = max(ans, it.fi);
                }
            }
        }
        for (int x : cur) {
            block[x] = 0;
        }
        cout << ans << "\n";
    }
}

signed main() {
    if (fopen(NAME".INP", "r")) {
        freopen(NAME".INP", "r", stdin);
        freopen(NAME".OUT", "w", stdout);
    }
    cin.tie(0)->sync_with_stdio(0);

    int t = 1;
    //cin >> t;
    while (t--) {
        input();
        solve();
    }

    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:102:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |         freopen(NAME".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:103:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |         freopen(NAME".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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