Submission #936307

#	Time	Username	Problem	Language	Result	Execution time	Memory
936307		Darren0724	Village (BOI20_village)	C++17	50 / 100	58 ms	20576 KiB

Village

#include <bits/stdc++.h>
using namespace std;
#define LCBorz ios_base::sync_with_stdio(false); cin.tie(0);
#define int long long
#define all(x) x.begin(), x.end()
#define endl '\n'
const int N=200005;
const int INF=1e18;
int n,mn=0,mx=0,total=0;
vector<int> adj[N],v(N),v1,sz(N,1);
vector<int> rec;
void dfs(int k,int pa){
    for(int j:adj[k]){
        if(j==pa)continue;
        dfs(j,k);
        if(v[j]==j){
            swap(v[j],v[k]);
            mn+=2;
        }
        sz[k]+=sz[j];
    }
}
int cen(int k,int pa){
    for(int j:adj[k]){
        if(j==pa)continue;
        if(sz[j]>n/2){
            return cen(j,k);
        }
    }
    return k;
}
void dfs1(int k,int pa,int deep){
    total+=deep*2;
    v1.push_back(k);
    for(int j:adj[k]){
        if(j==pa)continue;
        dfs1(j,k,deep+1);
    }
}
int32_t main() {
    LCBorz;
    cin>>n;
    for(int i=1;i<n;i++){
        int a,b;cin>>a>>b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    iota(all(v),0);
    dfs(1,1);
    if(v[1]==1){
        swap(v[1],v[adj[1][0]]);
        mn+=2;
    }
    int c=cen(1,1);
    dfs1(c,c,0);
    mx=total;
    rotate(v1.begin(),v1.begin()+n/2,v1.end());
    cout<<mn<<' '<<mx<<endl;
    for(int i=1;i<=n;i++){
        cout<<v[i]<<' ';
    }
    cout<<endl;
    for(int i=0;i<n;i++){
        cout<<v1[i]<<' ';
    }
    cout<<endl;
    return 0;
}

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