Submission #1215290

#	Time	Username	Problem	Language	Result	Execution time	Memory
1215290		KindaGoodGames	Spring cleaning (CEOI20_cleaning)	C++17	34 / 100	1094 ms	15688 KiB

cleaning

#include<bits/stdc++.h>

#define ll long long
#define pii pair<int,int>
#define tiii tuple<int,int,int>

using namespace std;

int n; 
vector<vector<int>> adj;
void DFS(int v, int p, vector<int>& dp, vector<vector<int>>& adj, vector<int>& arr){
    dp[v] = arr[v];
    if(adj[v].size() == 1 && arr[v] == 0){
        dp[v]++;
    }

    for(auto u : adj[v]){
        if(u == p) continue;
        DFS(u,v,dp,adj,arr);
        dp[v] += dp[u];
    }
}

int solve(vector<vector<int>>& adj, int d){
    vector<int> arr(n);
    for(int i = 0; i < d; i++){
        int a;
        cin >> a;
        a--;
        arr[a]++;
    }

    int r = 0;
    for(int i = 0; i < n; i++){
        if(adj[i].size() > 1){
            r = i;
            break;
        }
    }
    
    vector<int> dp(n);
    DFS(r,r,dp,adj, arr);

    if(dp[r] % 2 == 1){
        return -1;
    }

    int cnt = 0;
    for(int i = 0; i < n; i++){
        if(dp[i] % 2 == 0){
            cnt++;
        }
    }

    return n + d + cnt - 2;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int q;
    cin >> n>> q;
    
    vector<vector<int>> adj(n);

    for(int i = 0; i < n-1; i++){
        int a,b;
        cin >> a >> b;
        a--;b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    while(q--){
        int d;
        cin >> d;
        cout << solve(adj, d) << "\n";
    }
}

• Subtask 1: 0 / 0
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 16 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 17
• Subtask 7: 0 / 30