Submission #1133721

#	Time	Username	Problem	Language	Result	Execution time	Memory
1133721		Gray	Min-max tree (BOI18_minmaxtree)	C++20	100 / 100	268 ms	77832 KiB

minmaxtree

#include <bits/stdc++.h>
#include <cassert>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld long double
#define ff first
#define ss second
#define ln "\n"
#define mp make_pair

#define INF 2e18
#define MOD 1e9+7

vector<pair<ll, ll>> up;
vector<vector<ll>> A;
vector<pair<ll, ll>> e, bound;

struct Kuhn{
    vector<vector<ll>> A;
    vector<ll> match, vis;
    ll na, nb, cnt;
    Kuhn(ll _na, ll _nb){
        na=_na; nb=_nb; cnt=0;
        match.resize(nb, -1); vis.resize(na, 0);
        A.resize(na);
    }
    void add_edge(ll u, ll v){
        A[u].push_back(v);
    }
    bool try_kuhn(ll u){
        if (vis[u]==cnt) return 0;
        vis[u]=cnt;
        for (auto v:A[u]){
            if (match[v]==-1){
                match[v]=u;
                return 1;
            }
        }
        for (auto v:A[u]){
            if (try_kuhn(match[v])){
                match[v]=u;
                return 1;
            }
        }
        return 0;
    }
    void run(){
        for (ll i=0; i<na; i++){
            cnt++;
            try_kuhn(i);
        }
    }
};

struct node{
    struct snode{
        ll v; pair<ll, ll> mn, mx;
        snode(){
            mn={-1, -1};
            mx={INF, -1};
        }
    }; ll ni;
    vector<snode> jump;
    node(){
        jump.resize(20);
    }
};

vector<node> bin; vector<ll> lev;

void genbin(ll u, ll p, ll lvl){
    lev[u]=lvl;
    bin[u].jump[0].v=p;
    for (ll i=1; i<20; i++) bin[u].jump[i] = bin[bin[u].jump[i-1].v].jump[i-1];
    for (auto i:A[u]){
        ll v = e[i].ff^e[i].ss^u;
        if (v==p) continue;
        bin[v].ni=i;
        genbin(v, u, lvl+1);
    }
}

ll getlca(ll u, ll v){
    if (lev[u]<lev[v]) swap(u, v);
    ll dif = lev[u]-lev[v];
    for (ll i=0; i<20; i++){
        if (dif&(1ull<<i)) u=bin[u].jump[i].v;
    }
    if (u==v) return u;
    for (ll i=19; i>=0; i--){
        if (bin[u].jump[i].v==bin[v].jump[i].v) continue;
        u=bin[u].jump[i].v; v=bin[v].jump[i].v;
    }
    return bin[u].jump[0].v;
}

void solve(){
    ll n; cin >> n;
    A.resize(n+1); e.resize(n-1); bound.resize(n-1, {-1, -1});
    for (ll i=0; i<n-1; i++){
        ll u, v; cin >> u >> v; e[i] = {u, v};
        A[u].push_back(i); A[v].push_back(i);
    }
    ll k; cin >> k; up.resize(k);
    bin.resize(n+1); lev.resize(n+1);
    genbin(1, 1, 0);
    for (ll i=0; i<k; i++){
        char typ; ll u, v, w; cin >> typ >> u >> v >> w;
        up[i] = {typ=='m', w};
        ll lca = getlca(u, v);
        for (auto node:{u, v}){
            ll dif = lev[node]-lev[lca];
            for (ll j=0; j<20; j++){
                if (dif&(1ull<<j)){
                    if (typ=='m') bin[node].jump[j].mn=max(mp(w, i), bin[node].jump[j].mn);
                    else bin[node].jump[j].mx = (bin[node].jump[j].mx==mp(-1ll, -1ll)?mp(w, i):min(bin[node].jump[j].mx, mp(w, i)));
                    node=bin[node].jump[j].v;
                }
            }
        }
    }

    for (ll i=19; i>=1; i--){
        // cout << i << ": ";
        for (ll j=1; j<=n; j++){
            // cout << j << "|" << bin[j].jump[i].mn.ss << "|" << bin[j].jump[i].mx.ss << " ";
            bin[j].jump[i-1].mn=max(bin[j].jump[i].mn, bin[j].jump[i-1].mn);
            bin[bin[j].jump[i-1].v].jump[i-1].mn=max(bin[j].jump[i].mn, bin[bin[j].jump[i-1].v].jump[i-1].mn);
            bin[j].jump[i-1].mx=min(bin[j].jump[i].mx, bin[j].jump[i-1].mx);
            bin[bin[j].jump[i-1].v].jump[i-1].mx=min(bin[j].jump[i].mx, bin[bin[j].jump[i-1].v].jump[i-1].mx);
        }
        // cout << ln;
    }
    for (ll i=0; i<n-1; i++){
        ll u = e[i].ff, v = e[i].ss;
        if (lev[u]<lev[v]) swap(u, v);
        bound[bin[u].ni].ff = bin[u].jump[0].mn.ss;
        bound[bin[u].ni].ss = bin[u].jump[0].mx.ss;
    }
    // for (ll i=0; i<n-1; i++){
    //     cout << i << ": " << bound[i].ff << " - " << bound[i].ss << ln;
    // }
    Kuhn match(k, n-1);
    for (ll i=0; i<n-1; i++){
        if (bound[i].ff!=-1) match.add_edge(bound[i].ff, i);
        if (bound[i].ss!=-1) match.add_edge(bound[i].ss, i);
    }
    match.run();
    for (ll i=0; i<n-1; i++){
        cout << e[i].ff << " " << e[i].ss << " ";
        if (match.match[i]==-1) cout << (bound[i].ff!=-1?up[bound[i].ff].ss:0) << ln;
        else cout << up[match.match[i]].ss << ln;
    }
}
int main(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    auto start = chrono::high_resolution_clock::now();
    ll t=1;
    // cin >> t;
    while (t--) solve();
    #ifdef LOCAL
    auto duration = chrono::duration_cast<chrono::microseconds>(chrono::high_resolution_clock::now() - start);
    cout << setprecision(0) << fixed << "time: " << (double)duration.count()/1000.0 << " milliseconds" << endl;
    #endif
}

• Subtask 1: 7 / 7
• Subtask 2: 22 / 22
• Subtask 3: 29 / 29
• Subtask 4: 42 / 42