Submission #1217037

#	Time	Username	Problem	Language	Result	Execution time	Memory
1217037		anonymous321	Spring cleaning (CEOI20_cleaning)	C++20	34 / 100	1097 ms	16200 KiB

cleaning

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

vector<vector<int>> adj_list;

vector<int> nleafs;
vector<int> dp;
vector<int> dpl;

void dfs (int v, int p) {
    dp[v] = 0;
    dpl[v] = 0;
    int cnt = 0;
    for (auto &it : adj_list[v]) {
        if (it == p) continue;
        cnt++;
        dfs(it, v);
        dpl[v] += dpl[it];
        dp[v] += 2 - (dpl[it] % 2);
        dp[v] += dp[it];
    }
    if (cnt == 0 && nleafs[v] == 0) dpl[v]++;
    if (cnt + nleafs[v] <= 1 && p == -1) dpl[v]++;
    dpl[v] += nleafs[v];
    dp[v] += nleafs[v];
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, q;
    cin >> n >> q;
    adj_list = vector<vector<int>> (n);
    for (int i = 0; i < n-1; i++) {
        int u, v;
        cin >> u >> v;
        adj_list[u-1].push_back(v-1);
        adj_list[v-1].push_back(u-1);
    }
    
    vector<vector<int>> va (q);
    for (int i = 0; i < q; i++) {
        int d;
        cin >> d;
        for (int j = 0; j < d; j++) {
            int a;
            cin >> a;
            va[i].push_back(a-1);
        }
    }
    
    nleafs = vector<int> (n, 0);
    dp = vector<int> (n, 0);
    dpl = vector<int> (n, 0);
    for (int i = 0; i < q; i++) {
        for (auto &it: va[i]) {
            nleafs[it]++;
        }
        dfs(0, -1);
        if (dpl[0] % 2 == 1) dp[0] = -1;
        cout << dp[0] << "\n";
        for (auto &it: va[i]) {
            nleafs[it]--;
        }
    }
    return 0;
}

• 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