Submission #658312

#	Time	Username	Problem	Language	Result	Execution time	Memory
658312		Kahou	Spring cleaning (CEOI20_cleaning)	C++14	34 / 100	1092 ms	13980 KiB

cleaning

#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define endl '\n'
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int N = 1e5 + 50;
int n, q, sub[N], ans;
bool om[N], mark[N];
vector<int> adj[N];

void dfs(int u, int p) {
        for (int v:adj[u]) {
                if (v == p) continue;
                dfs(v, u);
                sub[u] += sub[v];
                ans += 1-(sub[v]&1);
        }
}

void solve() {
        cin >> n >> q;
        for (int i = 1; i <= n-1; i++) {
                int u, v;
                cin >> u >> v;
                adj[u].push_back(v);
                adj[v].push_back(u);
        }
        int r = 0;
        for (int u = 1; u <= n; u++) {
                if(adj[u].size() > 1) {
                        if (!r) r = u;
                }
                else {
                        om[u] = 1;
                }
        }
        for (int u = 1; u <= n; u++) {
                mark[u] = om[u];
                sub[u] = om[u];
        }

        while (q--) {
                int d;
                cin >> d;
                for (int i = 1; i <= d; i++) {
                        int u;
                        cin >> u;
                        sub[u]++;
                        if (mark[u]) {
                                sub[u]--;
                                mark[u] = 0;
                        }
                }
                dfs(r, 0);
                cout << (sub[r]&1? -1: n+d-1+ans) << endl;

                for (int u = 1; u <= n; u++) {
                        mark[u] = om[u];
                        sub[u] = om[u];
                }
                ans = 0;
        }
}

int main() {
        ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
        solve();
        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