Submission #1244026

#	Time	Username	Problem	Language	Result	Execution time	Memory
1244026		Malix	Village (BOI20_village)	C++20	50 / 100	89 ms	17916 KiB

Village

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef pair<int,int> pi;
typedef vector<pi> pii;
typedef tuple<int,int,int> ti;
typedef vector<ll> li;
typedef vector<li> lii;
 
#define REP(i,a,b) for(int i=a;i<b;i++)
#define F first
#define S second
#define PB push_back
#define LSOne(s) ((s)&(-s))
#define all(x) (x).begin(),(x).end()
 
ll INF=1000000000000000010;
int inf=1e9+10;
ll M=1e9+7;

vii a;
vi p,c,s,d;

void dfs(int x){
    for(auto u:a[x])if(u!=p[x]){
        c[x]++;
        p[u]=x;
        d[u]=d[x]+1;
        dfs(u);
        s[x]+=s[u];
    }
}

int centroid(int x,int y){
    for(auto u:a[x])if(s[u]>y/2){
        s[x]-=s[u];
        s[u]=y;
        return centroid(u,y);
    }
    return x;
}

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    int n;cin>>n;
    a.resize(n);p.resize(n,-1);c.resize(n,0);s.resize(n,1);d.resize(n,0);
    REP(i,0,n-1){
        int x,y;cin>>x>>y;
        x--;y--;
        a[x].PB(y);
        a[y].PB(x);
    }
    dfs(0);
    queue<int> q;
    REP(i,0,n)if(c[i]==0)q.push(i);
    ll cnt=0,cnt2=0;
    vi ans(n),ans2(n);
    REP(i,0,n)ans[i]=i;
    ans2=ans;
    while(!q.empty()){
        int x=q.front();
        q.pop();
        if(ans[x]!=x){
            if(x!=0){
                c[p[x]]--;
                if(c[p[x]]==0)q.push(p[x]);
            }
            continue;
        }
        cnt+=2;
        if(x==0)swap(ans[x],ans[a[0][0]]);
        else{
            swap(ans[x],ans[p[x]]);
            c[p[x]]--;
            if(c[p[x]]==0)q.push(p[x]);
        }
    }
    int x=centroid(0,n);
    p.clear();s.clear();d.clear();c.clear();
    p.resize(n,-1);c.resize(n,0);s.resize(n,1);d.resize(n,0);
    dfs(x);
    REP(i,0,n)cnt2+=(ll)d[i]*2LL;
    vi vis(n,0);
    vis[x]=1;
    vii b;
    for(auto u:a[x]){
        vi arr;
        queue<int> q;
        q.push(u);
        while(!q.empty()){
            int y=q.front();
            q.pop();
            vis[y]=1;
            arr.PB(y);
            for(auto v:a[y])if(!vis[v])q.push(v);
        }
        b.PB(arr);
    }
    int l=0,r=1,sz=b.size();
    while(r<sz){
        while(!b[l].empty()&&!b[r].empty()){
            swap(ans2[b[l].back()],ans2[b[r].back()]);
            b[l].pop_back();
            b[r].pop_back();
        }
        if(b[l].empty()&&b[r].empty()){
            l=r+1;r=l+1;
        }
        else if(b[l].empty()){
            l=r;r=l+1;
        }
        else r++;
    }
    if(l<sz&&!b[l].empty())swap(ans2[x],ans2[b[l][0]]);
    else if(r<sz&&!b[r].empty())swap(ans2[x],ans2[b[r][0]]);
    else swap(ans2[x],ans2[(x+1)%n]);
    cout<<cnt<<" "<<cnt2<<"\n";
    for(auto u:ans)cout<<u+1<<" ";
    cout<<"\n";
    for(auto u:ans2)cout<<u+1<<" ";
}

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