제출 #1239074

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1239074		mychecksedad	Highway Tolls (IOI18_highway)	C++20	100 / 100	117 ms	14624 KiB

highway

#include "highway.h"
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define vi vector<int>
#define ff first
#define all(x) x.begin(),x.end()
#define ss second
#define ll long long int
#define pii pair<int,int>
const int N = 2e5+100;

int s[N], dep[N], PAR[N];
vector<pii> g[N];
bitset<N> VIS;


void find_pair(int n, std::vector<int> U, std::vector<int> V, int A, int B) {
  int m = U.size();

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

  vi w(m);
  ll val = ask(w);
  int k = val / A;

  int l = 0, r = m - 2, res = m-1;
  while(l <= r){
    int mid = l+r>>1;
    w.clear();
    w.resize(m);
    for(int j = 0; j <= mid; ++j) w[j] = 1;
    ll y = ask(w);
    if(y != val){
      res = mid;
      r = mid - 1;
    }else{
      l = mid + 1;
    }
  }

  int x = U[res];
  int y = V[res];

  queue<int> q;
  q.push(x);
  vector<int> D(n, -1);
  vector<int> D1(n, -1);
  vi par1(n, -1);
  vi par2(n, -1);
  D[x] = 0;
  while(!q.empty()){
    int v = q.front(); 
    q.pop();
    for(auto [u, id]: g[v]){
      if(D[u] == -1){
        D[u] = D[v] + 1;
        par1[u] = id;
        q.push(u);
      }
    }
  }
  q.push(y);
  D1[y] = 0;
  while(!q.empty()){
    int v = q.front(); 
    q.pop();
    for(auto [u, id]: g[v]){
      if(D1[u] == -1){
        D1[u] = D1[v] + 1;
        par2[u] = id;
        q.push(u);
      }
    }
  }


  vector<pii> X, Y;
  for(int i = 0; i < n; ++i){
    if(D[i] < D1[i]) X.pb({D[i], i});
    else if(D1[i] < D[i]) Y.pb({D1[i], i});
  }
  sort(all(X));
  int ress = res;
  l = 0, r = int(X.size()) - 1, res = 0;
  while(l <= r){
    int mid = l+r>>1;
    w.clear();
    w.resize(m, 1);
    for(auto [d, v]: Y) if(par2[v] != -1) w[par2[v]] = 0;
    w[ress] = 0;
    for(int i = 0; i <= mid; ++i) if(par1[X[i].ss] != -1) w[par1[X[i].ss]] = 0;
    ll y = ask(w);
    if(y == val){
      res = mid;
      r = mid - 1;
    }else{
      l = mid + 1;
    }
  }
  int s = X[res].ss;
  sort(all(Y));
  l = 0, r = int(Y.size()) - 1, res = 0;
  while(l <= r){
    int mid = l+r>>1;
    w.clear();
    w.resize(m, 1);
    for(auto [d, v]: X) if(par1[v] != -1) w[par1[v]] = 0;
    w[ress] = 0;
    for(int i = 0; i <= mid; ++i) if(par2[Y[i].ss] != -1) w[par2[Y[i].ss]] = 0;
    ll y = ask(w);
    if(y == val){
      res = mid;
      r = mid - 1;
    }else{
      l = mid + 1;
    }
  }
  int t = Y[res].ss;

  // cerr << s << ' ' << t << '\n';

  answer(s, t);
}

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