Submission #578093

#	Time	Username	Problem	Language	Result	Execution time	Memory
578093		talant117408	Spring cleaning (CEOI20_cleaning)	C++17	0 / 100	1016 ms	15188 KiB

cleaning

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;

#define long                unsigned long 
#define pb                  push_back
#define mp                  make_pair
#define all(v)              (v).begin(),(v).end()
#define rall(v)             (v).rbegin(),(v).rend()
#define lb                  lower_bound
#define ub                  upper_bound
#define sz(v)               int((v).size())
#define do_not_disturb      ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define endl                '\n'

const int N = 2e5+7;
vector <vector <int>> graph(N), new_graph(N);
int used[N], depth[N], root;
ll ans;

vector <pii> dfs(int v, int p) {
    vector <pii> leaves;
    for (auto to : new_graph[v]) {
        if (to == p) {
            continue;
        }
        depth[to] = depth[v] + 1;
        auto tmp = dfs(to, v);
        for (auto x : tmp) leaves.pb(x);
    }
    sort(all(leaves), [&](pii a, pii b) {
        return depth[a.first] < depth[b.first];
    });
    if (v == root) {
        if (sz(leaves)&1) return leaves;
        
        for (int i = 0; i < sz(leaves); i++) {
            auto x = leaves[i];
            ans += depth[x.first]-depth[v];
        }
        return vector <pii> (0);
    }
    else {
        if (sz(leaves) == 0) {
            leaves.pb(mp(v, v));
            return leaves;
        }
        vector <pii> ret;
        ret.pb(mp(leaves.back().first, v));
        leaves.pop_back();
        if (sz(leaves)&1) {
            ret.pb(mp(leaves.back().first, v));
            leaves.pop_back();
        }
        for (int i = 0; i < sz(leaves); i++) {
            auto x = leaves[i];
            ans += depth[x.first]-depth[v];
        }
        return ret;
    }
}

int get(int n) {
    ans = 0;
    for (int i = 1; i <= n; i++) {
        used[i] = 0;
        if (sz(new_graph[i]) > 1) {
            root = i;
        }
    }
    auto tmp = dfs(root, root);
    if (sz(tmp)) return -1;
    else return ans;
}

void solve() {
    int n, q;
    cin >> n >> q;
    for (int i = 1; i < n; i++) {
        int a, b;
        cin >> a >> b;
        graph[a].pb(b);
        graph[b].pb(a);
    }
    if (n <= 20000 && q <= 300) {
        while (q--) {
            int vertex = n+1;
            int k;
            cin >> k;
            for (int i = 1; i <= n+k; i++) {
                new_graph[i].clear();
                for (auto to : graph[i]) new_graph[i].pb(to);
            }
            while (k--) {
                int x;
                cin >> x;
                new_graph[x].pb(vertex);
                new_graph[vertex].pb(x);
                vertex++;
            }
            cout << get(vertex-1) << endl;
        }
    }
}

int main() {
    do_not_disturb
    
    int t = 1;
    //~ cin >> t;
    while (t--) {
        solve();
    }
    
    return 0;
}

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