Submission #955705

#	Time	Username	Problem	Language	Result	Execution time	Memory
955705		aymanrs	Jail (JOI22_jail)	C++14	21 / 100	5086 ms	1368 KiB

jail

#include<bits/stdc++.h>
using namespace std;
bool f; int t;
void dfs(int n, vector<int> g[], int p, vector<int>& path){
    path.push_back(n);
    if(n == t){
        f = true;
        return;
    }
    for(int c : g[n]){
        if(f) break;
        if(c == p) continue;
        dfs(c, g, n, path);
    }
    if(!f) path.pop_back();
}
void solve(){
    int n,m;cin >> n;
    vector<int> g[n+1];
    for(int i = 1;i < n;i++){
        int u, v;cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    cin >> m;
    vector<int> path[m];
    int o[m];for(int i = 0;i < m;i++) o[i] = i;
    for(int i = 0;i < m;i++){
        int s;cin >> s >> t;f = false;
        dfs(s, g, -1, path[i]);
    }
    do {
        bool occ[n+1] = {false};
        for(int i = 0;i < m;i++) occ[path[i][0]] = true;
        f = true;
        for(int _ = 0;_ < m && f;_++){
            int i = o[_];
            occ[path[i][0]] = false;
            for(int k : path[i]) {
                if(occ[k]){
                    f = false;
                    break;
                }
            }
            occ[path[i].back()] = true;
        }
        if(f) {
            cout << "Yes\n";
            return;
        }
    } while(next_permutation(o, o+m));
    cout << "No\n";
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int t;cin >> t;
    while(t--) solve();
}

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