Submission #1278157

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278157		glupan	Village (BOI20_village)	C++20	50 / 100	96 ms	28172 KiB

Village

#include <bits/stdc++.h>

using namespace std;

#define ll long long

const int MAX_N = 100005;

vector<int>adj[MAX_N];
int visited[MAX_N],ans;
int order[MAX_N],cnt=1;

void dfs(int s, int p) {
    for(int u : adj[s]) {
        if(u == p) continue;
        dfs(u,s);
    }
    if(!visited[s] and !visited[p] and s and p) {
        visited[s] = p;
        visited[p] = s;
        ans+=2;
    }
}

void dfs2(int s, int p) {
    order[cnt++] = s;
    for(int u : adj[s]) {
        if(u == p) continue;
        dfs2(u,s);
    }
}

void solve() {
    int n; cin >> n;
    for(int i=0; i<n-1; i++) {
        int a,b; cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    dfs(1,0);
    for(int i=1; i<=n; i++) {
        if(!visited[i]) {
            visited[i] = i;
            swap(visited[i], visited[adj[i][0]]);
            ans+=2;
        }
    }
    cout << ans << " " << ans << endl;
    for(int i=1; i<=n; i++) cout << visited[i] << " ";
    cout << endl;
    dfs2(1,0);
    int Ans[n+1];
    for(int i=1; i<=n; i++) {
        int tmp = (i+n/2)%n;
        if(tmp == 0) tmp = n;
        Ans[order[i]] = order[tmp];
    }
    for(int i=1; i<=n; i++) cout << Ans[i] << " ";
    cout << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    int t=1;
    while(t--) solve();
}

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