Submission #582421

#	Time	Username	Problem	Language	Result	Execution time	Memory
582421		Vanilla	Highway Tolls (IOI18_highway)	C++17	5 / 100	120 ms	7716 KiB

highway

#include <bits/stdc++.h>
#include "highway.h"
typedef long long int64;
using namespace std;
const int maxn = 9e4 + 2;
const int maxm = 13e4 + 2;
vector <pair <int, int> > ad [maxn];
vector <int> w;
int n;
int64 len, a, b, lastlen = 1e9;
bool done = 0;

void dfs (int u, int p, int64 d = 0) {
  if (done || u > lastlen) return;
  if (d == len) {
    lastlen = ask(w) / b;
    if (lastlen == len){
      answer(0, u);
      done = 1;
    }
    return;
  }
  for (pair <int, int> v: ad[u]) {
    if (v.first == p) continue;
    w[v.second] = 1;
    dfs(v.first, u, d + 1);
    if (lastlen == d) lastlen = 1e9;
    w[v.second] = 0;
  }
}

void find_pair(int N, vector<int> u, vector<int> v, int A, int B) {
  int m = u.size();
  n = N, a = A, b = B;
  for (int i = 0; i < m; i++){
    ad[u[i]].push_back({v[i], i});
    ad[v[i]].push_back({u[i], i});
  }
  for (int i = 0; i < m; i++){
    w.push_back(0);
  }
  len = ask(w) / a;
  dfs(0, -1);
  assert(done);
}

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