Submission #890877

#	Time	Username	Problem	Language	Result	Execution time	Memory
890877		vjudge1	Jail (JOI22_jail)	C++17	0 / 100	1 ms	348 KiB

jail

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(), x.end()
#define size(x) (int)x.size()

template<class S, class T>
bool chmin(S &a, const T &b) {
    return a > b && (a = b) == b;
}
template<class S, class T>
bool chmax(S &a, const T &b) {
    return a < b && (a = b) == b;
}
const int inf = 1e9 + 7;
const int INF = 1e18 + 7;
const int mod = 998244353;

void Main() {
    int n;
    cin >> n;
    vector<int> g[n];
    for (int i = 1; i < n; ++i) {
        int a, b;
        cin >> a >> b;
        a--, b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    int root = -1, position = -1;
    vector<int> pos(n);
    vector<bool> used(n, false);
    for (int i = 0; i < n; ++i) {
        if (size(g[i]) == 1) {
            root = i;
            break;
        }
    }
    function<void(int, int)> dfs = [&](int v, int p) {
        pos[v] = ++position;
        for (int to : g[v]) {
            if (to != p) {
                dfs(to, v);
            }
        }
    };
    dfs(root, -1);
    bool flag = true;
    deque<pair<int, int>> l, r;
    int m;
    cin >> m;
    while (m--) {
        int s, t;
        cin >> s >> t;
        s--, t--;
        if (pos[t] > pos[s]) {
            r.push_back({pos[t], pos[s]});
        } else {
            l.push_back({pos[t], pos[s]});
        }
        used[pos[s]] = true;
    }
    sort(all(l)), sort(all(r));
    while (!l.empty()) {
        int s = l.front().second, t = l.front().first;
        l.pop_front();
        used[s] = false;
        while (s > t) {
            if (used[s]) {
                flag = false;
                break;
            }
            s--;
        }
        used[t] = true;
    }
    while (!r.empty()) {
        int s = r.back().second, t = r.back().first;
        r.pop_back();
        used[s] = false;
        while (s < t) {
            if (used[s]) {
                flag = false;
                break;
            }
            s++;
        }
        used[t] = true;
    }
    cout << (flag ? "Yes" : "No") << '\n';
}

signed main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int q;
    cin >> q;
    while (q--) {
        Main();
    }
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 16
• Subtask 4: 0 / 28
• Subtask 5: 0 / 12
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23