Submission #916720

#	Time	Username	Problem	Language	Result	Execution time	Memory
916720		ParsaGolestani	Bitaro’s Party (JOI18_bitaro)	C++14	100 / 100	751 ms	272468 KiB

bitaro

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

const int N = 100'000;
const int SQ = 316;
const int INF = 1'000'000'000;

int n, m, q, mark[N + 10], dis[N + 10];
pair<int, int> far[N + 10][SQ + 10];
vector<pair<int, int>> in[N + 10];
vector<int> out[N + 10];

void readInput() {
    cin >> n >> m >> q;
    for (int i = 1; i <= m; i++) {
        int u, v;
        cin >> u >> v;
        out[u].push_back(v);
        in[v].push_back({u, 0});
    }
}

void calcFar(int u) {
    for (int j = 1; j <= SQ; j++) {
        far[u][j] = {-INF, 0};
        for (int k = 0; k < in[u].size(); k++) {
            int v = in[u][k].first;
            while (in[u][k].second < SQ && mark[far[v][in[u][k].second + 1].second])
                in[u][k].second++;
            if (in[u][k].second < SQ)
                far[u][j] = max(far[u][j], far[v][in[u][k].second + 1]);
        }
        far[u][j].first += (far[u][j].first == -INF? 0: 1);
        if (far[u][j].second)
            mark[far[u][j].second] = true;
    }
    for (int j = 1; j <= SQ; j++)
        if (far[u][j].first < 0) {
            far[u][j] = {0, u};
            break;
        }
    for (int j = 1; j <= SQ; j++)
        mark[far[u][j].second] = false;
}

void calcFar() {
    for (int i = 1; i <= n; i++)
        calcFar(i);
}

void query() {
    int u, cnt;
    cin >> u >> cnt;
    vector<int> vec;
    for (int i = 1; i <= cnt; i++) {
        int v;
        cin >> v;
        vec.push_back(v);
        mark[v] = true;
    }
    if (cnt < SQ) {
        for (int i = 1; i <= SQ; i++)
            if (!mark[far[u][i].second]) {
                cout << (far[u][i].first < 0? -1: far[u][i].first) << '\n';
                break;
            }
    }
    else {
        fill(dis + 1, dis + u + 1, -INF);
        dis[u] = 0;
        int ans = (mark[u]? -1: 0);
        for (int i = u - 1; i >= 1; i--) {
            for (auto v: out[i])
                if (v <= u)
                    dis[i] = max(dis[i], dis[v] + 1);
            if (!mark[i])
                ans = max(ans, dis[i]);
        }
        cout << ans << '\n';
    }
    for (auto x: vec)
        mark[x] = false;
}

void solve() {
    while (q--)
        query();
    cout.flush();
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    readInput();
    calcFar();
    solve();
    return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'void calcFar(int)':
bitaro.cpp:26:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |         for (int k = 0; k < in[u].size(); k++) {
      |                         ~~^~~~~~~~~~~~~~

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