Submission #575598

#	Time	Username	Problem	Language	Result	Execution time	Memory
575598		talant117408	Village (BOI20_village)	C++17	50 / 100	118 ms	20676 KiB

Village

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

void solve() {
    int n;
    cin >> n;
    vector <int> graph[n];
    for (int i = 0; i < n-1; i++) {
        int a, b;
        cin >> a >> b;
        a--; b--;
        graph[a].pb(b);
        graph[b].pb(a);
    }
    
    int cost[2];
    cost[0] = cost[1] = 0;
    vector <vector <int>> rear(2, vector <int> (n, -1));
    
    function <int(int, int)> find_smallest = [&](int v, int p) {
        vector <int> children;
        for (auto to : graph[v]) {
            if (to == p) continue;
            if (find_smallest(to, v)) {
                children.pb(to);
            }
        }
        if (sz(children) == 0) {
            if (v) return 1;
            cost[0] += 2;
            int x = graph[v][0];
            rear[0][v] = rear[0][x];
            rear[0][x] = v;
        }
        else if (sz(children)&1) {
            cost[0] += int(sz(children)/2)*4+2;
            rear[0][v] = children[0];
            rear[0][children[0]] = v;
            for (int i = 1; i < sz(children); i += 2) {
                rear[0][children[i]] = children[i+1];
                rear[0][children[i+1]] = children[i];
            }
        }
        else {
            cost[0] += sz(children)*2;
            rear[0][v] = children[1];
            rear[0][children[1]] = children[0];
            rear[0][children[0]] = v;
            for (int i = 2; i < sz(children); i += 2) {
                rear[0][children[i]] = children[i+1];
                rear[0][children[i+1]] = children[i];
            }
        }
        return 0;
    };
    find_smallest(0, 0);
    
    cout << cost[0] << ' ' << cost[1] << endl;
    for (int i = 0; i < 2; i++) {
        for (auto to : rear[i]) cout << (to == -1 ? to+2 : to+1) << ' ';
        cout << endl;
    }
}

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

• Subtask 1: 6 / 12
• Subtask 2: 19 / 38
• Subtask 3: 25 / 50