Submission #1218206

#	Time	Username	Problem	Language	Result	Execution time	Memory
1218206		__moin__	Spring cleaning (CEOI20_cleaning)	C++20	28 / 100	1095 ms	21492 KiB

cleaning

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

// #define int long long
const int INF = 1e9;

int clamp(int x) {
    return min(x, INF);
}

        vector<int> dp(2e5);
        vector<bool> par(2e5);
        vector<int> parent(2e5);

__int32_t main() {
    ios::sync_with_stdio(0); cin.tie(0);

    int n,q; cin >> n >> q;
    vector<vector<int>> adj(n);
    for (int i = 1; i < n; i++) {
        int a, b; cin >> a >> b; a--; b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    function<void(int,int)> dfs = [&](int v, int p) {
        parent[v] = p;
        bool thispar = adj[v].size() == 1;
        int sum = 0;
        for (int nn : adj[v]) {
            if (nn != p) {
                dfs(nn, v);
                thispar ^= par[nn];
                sum += dp[nn];
            }
        }
        par[v] = thispar;
        dp[v] = sum + (2 - par[v]);
    };
    dfs(0, -1);

    // ONE QUERY ONLY
    for (int Q = 0; Q < q; Q++) {
        // auto adj_local = adj;
        int m; cin >> m;
        vector<int> revert(m);
        vector<bool> marked(n+m);
        for (int i = 0; i < m; i++) {
            int x; cin >> x; x--;
            revert[i] = x;
            adj.push_back({x});
            adj[x].push_back(n++);
            marked[n-1] = 1;
            while (x != -1) {
                marked[x] = 1;
                x = parent[x];
            }
        }
        function<void(int,int)> dfs2 = [&](int v, int p) {
            if (!marked[v]) return;
            bool thispar = adj[v].size() == 1;
            int sum = 0;
            for (int nn : adj[v]) {
                if (nn != p) {
                    dfs2(nn, v);
                    thispar ^= par[nn];
                    sum += dp[nn];
                }
            }
            par[v] = thispar;
            dp[v] = sum + (2 - par[v]);
        };
        dfs2(0, -1);
        if (par[0]) cout << -1 << "\n";
        else cout << dp[0] - 2 + par[0] << "\n";
        n -= m;
        adj.resize(n);
        for (int e : revert) adj[e].pop_back();
        dfs2(0, -1);
    }


    return 0;
}

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