Submission #612141

#	Time	Username	Problem	Language	Result	Execution time	Memory
612141		daria	Stations (IOI20_stations)	C++14	0 / 100	990 ms	708 KiB

stations

#include"bits/stdc++.h"
#include "stations.h"
#include <vector>
using namespace std;

const int N = 1000;
const int INF = 5000;

int T;
vector<int> adj[N], lb_a(N), lb_c(N);
vector<bool> vis(N);

void dfs(int s, bool b){ //b = 0 apertura, b = 1 chiusura
 if(vis[s]) return;
 vis[s] = 1;
 if(!b) lb_a[s] = T++;
 for(int u : adj[s]) dfs(u, 1-b);
 if(b) lb_c[s] = T++;
}

vector<int> label(int n, int k, vector<int> u, vector<int> v) {
 for(int i=0; i<n; ++i) adj[i].clear();
 lb_a.resize(n);
 lb_c.resize(n);
 fill(lb_a.begin(), lb_a.end(), INF);
 fill(lb_c.begin(), lb_c.end(), INF);
 fill(vis.begin(), vis.end(), 0);
 T = 0;

 for(int i=0; i<n-1; ++i){
  adj[u[i]].push_back(v[i]);
  adj[v[i]].push_back(u[i]);
 }
 dfs(0, 0);

 vector<int> lb(n);
 map<int, int> mp_a, mp_c;
 for(int i=0; i<n; ++i) mp_a[lb_a[i]] = i;
 sort(lb_a.begin(), lb_a.end());
 for(int i=0; i<n; ++i){
  if(mp_a[i] == INF) break;
  int j = mp_a[i];
  lb[j] = i;
 }
 for(int i=0; i<n; ++i) mp_c[lb_c[i]] = i;
 sort(lb_c.begin(), lb_c.end());
 for(int i=0; i<n; ++i){
  if(mp_c[i] == INF) break;
  int j = mp_c[i];
  lb[j] = i+N;
 }
 //for(int i=0; i<n; ++i) cout << i << " " << lb[i] << endl;
 return lb;
}

int find_next_station(int s, int t, vector<int> c) {
 int par=-1;
 if(s < N){ //s apertura
  // le altre sono tutte chiusure
  par = 0;
  for(int u : c) par = max(par, u);
  if(t>=N) t-=N;
  if(t < s) return par;
  t+=N;
  for(int i=0; i<c.size(); ++i) if(c[i] >= t) return c[i];
 } else{ // s chiusura
  // le altre sono tutte aperture
  par = 400001;
  for(int u : c) par = min(par, u);
  if(t<N) t+=N;
  if(t > s) return par;
  t-=N;
  for(int i=c.size()-1; i>=0; --i) if(c[i] <= t) return c[i];
 }
 return par;
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:65:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |   for(int i=0; i<c.size(); ++i) if(c[i] >= t) return c[i];
      |                ~^~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 0 / 10
• Subtask 5: 0 / 61