Submission #955126

#	Time	Username	Problem	Language	Result	Execution time	Memory
955126		GrindMachine	Village (BOI20_village)	C++17	50 / 100	57 ms	17228 KiB

Village

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

vector<ll> adj[N];
vector<ll> subsiz(N);

void dfs1(ll u, ll p){
    subsiz[u] = 1;
    trav(v,adj[u]){
        if(v == p) conts;
        dfs1(v,u);
        subsiz[u] += subsiz[v];
    }
}

ll dfs2(ll u, ll p){
    trav(v,adj[u]){
        if(v == p) conts;
        if(subsiz[v] > subsiz[1]/2){
            return dfs2(v,u);
        }
    }

    return u;
}

vector<ll> here[N];
ll cost2 = 0;

void dfs3(ll u, ll p, ll r, ll d){
    here[r].pb(u);
    cost2 += d;
    trav(v,adj[u]){
        if(v == p) conts;
        dfs3(v,u,r,d+1);
    }
}

void solve(int test_case)
{
    ll n; cin >> n;
    rep1(i,n-1){
        ll u,v; cin >> u >> v;
        adj[u].pb(v), adj[v].pb(u);
    }

    dfs1(1,-1);
    ll c = dfs2(1,-1);

    trav(v,adj[c]){
        dfs3(v,c,v,1);
    }

    cost2 *= 2;

    priority_queue<pll> pq;
    trav(v,adj[c]){
        pq.push({sz(here[v]),v});
    }

    vector<ll> ans2(n+5,-1);

    rep1(iter,(n-2)/2){
        auto [s1,v1] = pq.top();
        pq.pop();
        auto [s2,v2] = pq.top();
        pq.pop();

        ll x = here[v1].back();
        ll y = here[v2].back();
        here[v1].pop_back();
        here[v2].pop_back();

        ans2[x] = y, ans2[y] = x;
        pq.push({s1-1,v1});
        pq.push({s2-1,v2});
    }

    vector<ll> remain;
    rep1(i,n){
        if(ans2[i] == -1){
            remain.pb(i);
        }
    }

    rep(i,sz(remain)){
        ans2[remain[i]] = remain[(i+1)%sz(remain)];
    }

    cout << 0 << " " << cost2 << endl;
    rep1(i,n) cout << 1 << " ";
    cout << endl;
    rep1(i,n) cout << ans2[i] << " ";
    cout << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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