Submission #1142320

#	Time	Username	Problem	Language	Result	Execution time	Memory
1142320		byunjaewoo	Highway Tolls (IOI18_highway)	C++20	88 / 100	120 ms	11476 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
using ll=long long;

const int N=90010;
int n, m, p, u, v, ans1, ans2, d[N];
bool chk[N];
ll dist;
vector<int> vs, vt;
queue<int> q;
vector<pair<int, int>> adj[N];

void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
  n=N, m=U.size();
  for(int i=0; i<m; i++) adj[U[i]].push_back({V[i], i}), adj[V[i]].push_back({U[i], i});
  vector<int> tmp(m, 0);
  dist=ask(tmp)/A;
  for(int s=0, e=m-1; s<e; ) {
    int mid=(s+e)/2;
    vector<int> tmp(m, 0);
    for(int j=0; j<=mid; j++) tmp[j]=1;
    if(ask(tmp)==dist*A) p=s=mid+1;
    else e=mid;
  }
  u=U[p], v=V[p];
  fill(d, d+n, N), d[u]=d[v]=0, q.push(u), q.push(-v);
  while(!q.empty()) {
    int curr=q.front(); q.pop();
    if(curr<0) {
      curr=-curr, chk[curr]=1;
      vt.push_back(curr);
      for(auto [next, w]:adj[curr]) if(d[next]==N) d[next]=d[curr]+1, q.push(-next);
      continue;
    }
    vs.push_back(curr);
    for(auto [next, w]:adj[curr]) if(d[next]==N) d[next]=d[curr]+1, q.push(next);
  }
  ans1=vs[0];
  for(int s=0, e=vs.size()-1; s<e; ) {
    int mid=(s+e)/2;
    vector<int> vis(n, 0), tmp(m, 0);
    for(int i=mid+1; i<vs.size(); i++) vis[vs[i]]=1;
    for(int i=mid+1; i<vs.size(); i++) for(auto [j, w]:adj[vs[i]])
      if(!vis[j]) tmp[w]=1;
    if(ask(tmp)==dist*A) e=mid;
    else s=mid+1, ans1=vs[mid+1];
  }
  ans2=vt[0];
  for(int s=0, e=vt.size()-1; s<e; ) {
    int mid=(s+e)/2;
    vector<int> vis(n, 0), tmp(m, 0);
    for(int i=mid+1; i<vt.size(); i++) vis[vt[i]]=1;
    for(int i=mid+1; i<vt.size(); i++) for(auto [j, w]:adj[vt[i]])
      if(!vis[j]) tmp[w]=1;
    if(ask(tmp)==dist*A) e=mid;
    else s=mid+1, ans2=vt[mid+1];
  }
  answer(ans1, ans2);
}

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