Submission #950882

#	Time	Username	Problem	Language	Result	Execution time	Memory
950882		vladilius	Jail (JOI22_jail)	C++17	0 / 100	1 ms	348 KiB

jail

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

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int q; cin>>q;
    while (q--){
        int n; cin>>n;
        vector<int> g[n + 1];
        for (int i = 1; i < n; i++){
            int a, b; cin>>a>>b;
            g[a].push_back(b);
            g[b].push_back(a);
        }
        int m; cin>>m;
        vector<int> s(m + 1), t(m + 1);
        for (int i = 1; i <= m; i++){
            cin>>s[i]>>t[i];
        }
        
        vector<int> tin(n + 1), tout(n + 1), pw[n + 1], pp(n + 1);
        int lg = ceil(log2(n)) + 2;
        for (int i = 1; i <= n; i++){
            pw[i].resize(lg);
        }
        int timer = 0;
        function<void(int, int)> fill = [&](int v, int pr){
            tin[v] = ++timer;
            pw[v][0] = pp[v] = pr;
            for (int i = 1; i < lg; i++){
                pw[v][i] = pw[pw[v][i - 1]][i - 1];
            }
            for (int i: g[v]){
                if (i == pr) continue;
                fill(i, v);
            }
            tout[v] = timer;
        };
        fill(1, 1);
        pp[1] = 0;
        
        auto check = [&](int x, int y){
            return (tin[x] <= tin[y] && tout[x] >= tout[y]);
        };
        auto lca = [&](int x, int y){
            if (check(x, y)) return x;
            if (check(y, x)) return y;
            for (int i = lg - 1; i >= 0; i--){
                if (!check(pw[x][i], y)){
                    x = pw[x][i];
                }
            }
            return pw[x][0];
        };
        
        vector<int> l(m + 1), d[n + 1];
        for (int i = 1; i <= m; i++){
            l[i] = lca(s[i], t[i]);
            d[s[i]].push_back(i);
        }
        
        vector<bool> vis(m + 1);
        vector<int> G[m + 1];
        function<void(int)> dfs = [&](int v){
            if (vis[v] || !v) return;
            vis[v] = true;
            int x = s[v];
            set<int> all;
            while (check(l[v], x)){
                for (int i: d[x]){
                    all.insert(i);
                }
                x = pp[x];
            }
            x = t[v];
            while (x != l[v]){
                for (int i: d[x]){
                    all.insert(i);
                }
                x = pp[x];
            }
            // all.erase(all.find(v));
            for (int i: all){
                if (i == v) continue;
                G[v].push_back(i);
                dfs(i);
            }
            d[s[v]].erase(find(d[s[v]].begin(), d[s[v]].end(), v));
            d[t[v]].push_back(v);
        };
        for (int i = 1; i <= m; i++) dfs(i);
        vis.assign(m + 1, false);
        bool out = true;
        function<void(int)> find = [&](int v){
            if (vis[v]){
                out = false;
                return;
            }
            vis[v] = true;
            for (int i: G[v]){
                find(i);
            }
        };
        vector<bool> used(m + 1);
        for (int i = 1; i <= m; i++){
            for (int j: G[i]){
                used[j] = true;
            }
        }
        for (int i = 1; i <= m; i++){
            if (used[i]) continue;
            find(i);
            if (!out) break;
        }
        for (int i = 1; i <= m; i++){
            if (!vis[i]){
                out = false;
                break;
            }
        }
        cout<<(out ? "Yes" : "No")<<"\n";
    }
}

• 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