제출 #288273

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
288273		andrew	통행료 (IOI18_highway)	C++17	18 / 100	286 ms	21188 KiB

highway

#include <bits/stdc++.h>
#include "highway.h"

#define fi first
#define se second
#define p_b push_back
#define m_p make_pair
#define sz(x) (int)x.size()
#define pii pair <int, int>
#define all(x) x.begin(),x.end()

using namespace std;
typedef long long ll;

vector < vector <pii> > v;
vector <int> p, tin, tout, nm, order, deep;
vector  <vector <int> > level;
int _timer;

void dfs(int x, int pr, int gl){
    p[x] = pr;
    tin[x] = ++_timer;
    order.p_b(x);
    deep[x] = gl;
    level[gl].p_b(x);
    for(auto to : v[x])if(to.fi != pr){
        dfs(to.fi, x, gl + 1);
        nm[to.fi] = to.se;
    }
    tout[x] = _timer;
}

void find_pair(int n, vector<int> U, vector<int> V, int A, int B) {
    int m = U.size();
    _timer = 0;
    tin.resize(n);
    tout.resize(n);
    p.resize(n);
    v.resize(n);
    nm.resize(n);
    deep.resize(n);
    level.resize(n);

    vector <int> w(m, 0);
    ll dist = ask(w);
    ll Len = dist / A;

    for(int i = 0; i < m; i++){
        v[U[i]].p_b({V[i], i});
        v[V[i]].p_b({U[i], i});
    }

    dfs(0, -1, 0);

    int Lca = -1;
    int l = 0, r = n - 1;
    while(l < r){
        int mid = (l + r) >> 1;
        fill(all(w), 0);
        for(int i = 0; i <= mid; i++){
            for(auto j : v[order[i]])if(j.fi != p[order[i]])w[j.se] = 1;
        }
        if(ask(w) == dist)l = mid + 1;
        else r = mid;
    }
    Lca = order[l];
    l = 0, r = n;
    while(l < r){
        int mid = (l + r) >> 1;
        fill(all(w), 0);
        for(int i = mid + 1; i < n; i++)w[nm[order[i]]] = 1;
        if(ask(w) != dist)l = mid + 1;
        else r = mid;
    }
    int S = order[l];
    int T = -1;
    int ost = Len - (deep[S] - deep[Lca]);
    vector <int> mb;
    for(int i : level[ost + deep[Lca]]){
        if(tin[Lca] <= tin[i] && tout[i] <= tout[Lca])mb.p_b(i);
    }
    l = 0, r = sz(mb) - 1;
    while(l < r){
        int mid = (l + r) >> 1;
        fill(all(w), 0);
        for(int i = 1; i < tin[mb[mid]]; i++)w[nm[order[i]]] = 1;;
        if(ask(w) < dist + ost * (B - A))l = mid + 1;
        else r = mid;

    }
    T = mb[l];
    answer(S, T);
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 6 / 6
• Subtask 4: 0 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31