Submission #683119

#	Time	Username	Problem	Language	Result	Execution time	Memory
683119		bleahbleah	Roller Coaster Railroad (IOI16_railroad)	C++17	30 / 100	869 ms	77564 KiB

railroad

#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
using namespace std;

using ll = long long;

//#define int ll
#define sz(x) ((int)(x).size())

using pii = pair<int,int>;
using tii = tuple<int,int,int>;

const int nmax = 5e5 + 5, inf = 1e9 + 5; 

vector<int> g[nmax];
bool occ[nmax];
void dfs(int node) {
  if(occ[node]) return;
  occ[node] = 1;
  for(auto x : g[node]) {
    dfs(x);
  }
  return;
}

long long plan_roller_coaster(vector<int> s, vector<int> t) {
  t.emplace_back(0);
  s.emplace_back(inf);
  
  unordered_map<int,int> nrm;
  map<int,int> smen;
  for(auto x : s)
    smen[x]++;
  for(auto x : t)
    smen[x]--;
  
  int edgc = 0;
  int last = 0, cnt = 0;
  
  for(auto [a, b] : smen)  {
    nrm[a] = cnt++;
    if(edgc != 0)
      g[nrm[a]].emplace_back(nrm[last]),
      g[nrm[last]].emplace_back(nrm[a]);
    edgc += b;
    if(edgc > 0) return 3;
    last = a;
    //cerr << a << ' ' << edgc << '\n';
  }
  for(int i = 0; i < sz(s); i++)
    g[nrm[s[i]]].emplace_back(nrm[t[i]]),
    g[nrm[t[i]]].emplace_back(nrm[s[i]]);
  dfs(0);
  for(auto x : s)
    if(occ[nrm[x]] == 0) return 3;
  for(auto x : t)
    if(occ[nrm[x]] == 0) return 3;
  return 0;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 23
• Subtask 3: 30 / 30
• Subtask 4: 0 / 36