Submission #920794

#	Time	Username	Problem	Language	Result	Execution time	Memory
920794		adaawf	Bitaro’s Party (JOI18_bitaro)	C++14	100 / 100	1756 ms	482796 KiB

bitaro

#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;
vector<pair<int, int>> a[100005];
vector<int> g[100005];
int h = 400, dd[100005], b[100005], f[100005];
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n, m, q;
    cin >> n >> m >> q;
    a[1].push_back({0, 1});
    for (int i = 1; i <= m; i++) {
        int u, v;
        cin >> u >> v;
        g[v].push_back(u);
    }
    memset(b, -1, sizeof b);
    for (int i = 1; i <= n; i++) {
        a[i].push_back({0, i});
        vector<int> v;
        for (int w : g[i]) {
            for (auto x : a[w]) {
                if (b[x.second] == -1) v.push_back(x.second);
                if (b[x.second] < x.first + 1) {
                    b[x.second] = x.first + 1;
                }
            }
        }
        for (int w : v) {
            a[i].push_back({b[w], w});
            b[w] = -1;
        }
        sort(a[i].begin(), a[i].end(), greater<pair<int, int>>());
        while (a[i].size() > h) a[i].pop_back();
    }
    for (int jj = 0; jj < q; jj++) {
        int x, y;
        cin >> x >> y;
        vector<int> v;
        for (int i = 0; i < y; i++) {
            int z;
            cin >> z;
            dd[z] = 1;
            v.push_back(z);
        }
        if (y < h) {
            int flag = 0;
            for (auto w : a[x]) {
                if (dd[w.second] == 0) {
                    cout << w.first;
                    flag = 1;
                    break;
                }
            }
            if (flag == 0) cout << -1;
        }
        else {
            for (int i = 1; i <= x; i++) {
                if (dd[i] == 1) {
                    f[i] = -1e9;
                }
                else f[i] = 0;
            }
            for (int i = 1; i <= x; i++) {
                for (int w : g[i]) {
                    f[i] = max(f[i], f[w] + 1);
                }
            }
            if (f[x] < 0) cout << -1;
            else cout << f[x];
        }
        cout << '\n';
        for (int w : v) dd[w] = 0;
    }
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:37:28: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   37 |         while (a[i].size() > h) a[i].pop_back();
      |                ~~~~~~~~~~~~^~~

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