Submission #1136454

#	Time	Username	Problem	Language	Result	Execution time	Memory
1136454		sinataghizadeh	Village (BOI20_village)	C++20	100 / 100	91 ms	17596 KiB

Village

#include <bits/stdc++.h>
using namespace std;

typedef long long       ll;
typedef pair<ll,ll>     pll;
#define fastio          cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
#define all(x)          (x).begin(),(x).end()
#define pb              push_back
#define fi              first
#define se              second
#define siz             size()
#define endl            '\n'
const   ll              inf = 1e18;
const   ll              maxn=1e5+5455;
ll cen,n,sub[maxn],p[maxn],a[maxn],ans,cnt;
vector<ll>g[maxn],vec;
queue<ll>q;
void dfsz(ll v,ll par) {
        sub[v]=1;
        for(auto u:g[v]){
                if(u==par)continue;
                dfsz(u,v);
                sub[v]+=sub[u];
        }
        if(v!=1)ans+=min(sub[v],n-sub[v]);
}
ll cent(ll v,ll par){
        for(auto u:g[v]){
                if(sub[u]*2>n && u!=par)return cent(u,v);
        }
        return v;
}
void dfs(ll v,ll par,ll r){
        p[v]=r;
        for(auto u:g[v]){
                if(u!=par){
                        dfs(u,v,r);
                }
        }
}
void fill(ll v,ll par) {
        vec.pb(v);
        for(auto u:g[v]){
                if(u!=par){
                        
                        fill(u,v);
                }
        }
}
void dfss(ll v,ll par){
        for(auto u:g[v]) {
                if(u==par)continue;
                dfss(u,v);
                if(a[u]==u){swap(a[v],a[u]);cnt+=2;}
        }
}
int main() {
        cin>>n;
        for(int i=1;i<n;i++){
                ll u,v;cin>>u>>v;
                g[u].pb(v);
                g[v].pb(u);
                q.push(i);
        }
        q.push(n);
        dfsz(1,-1);
        cen=cent(1,-1);
        vector<pll>x;
        ll pp=ans;
        dfsz(cen,-1);ans=pp;
        for(auto v:g[cen]){
                dfs(v,cen,v);
                x.pb({sub[v],v});
        }
        sort(all(x));
        reverse(all(x));
        for(auto [j,v]:x){
                vec.clear();
                fill(v,cen);
                for(auto u:vec){
                        while(a[u]==0){
                                ll b=q.front();
                                q.pop();
                                if(p[b]!=p[u])a[u]=b;
                                else q.push(b);
                        }
                }
        }
        a[cen]=q.front();
        if(a[cen]==cen){
                swap(a[cen],a[g[cen][0]]);
        }
        ll c[n+2];
        c[0]=ans*2;
        for(int i=1;i<=n;i++){c[i]=a[i];a[i]=i;}
        ll d[n+2];
        dfss(1,-1);
        if(a[1]==1){
                cnt+=2;
                ll u=g[1][0];swap(a[1],a[u]);
        }
        cout<<cnt<<" "<<c[0]<<endl;
        for(int i=1;i<=n;i++)cout<<a[i]<<" ";
        cout<<endl;
        for(int i=1;i<=n;i++)cout<<c[i]<<" ";
}

• Subtask 1: 12 / 12
• Subtask 2: 38 / 38
• Subtask 3: 50 / 50