Submission #1051482

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051482		abczz	Parachute rings (IOI12_rings)	C++17	37 / 100	1411 ms	187932 KiB

rings

#include <iostream>
#include <map>
#include <vector>
#define ll long long

using namespace std;

map <ll, ll> mp;
vector <ll> adj[1000000], V;
ll n, x, y, tot, P[1000000], cyc[1000000], deg[1000000];
ll dsu(ll u) {
  if (P[u] == u) return u;
  else return P[u] = dsu(P[u]);
}
void Init(int N_) {
  n = N_;
  tot = 0;
  mp.clear();
  for (int i=0; i<n; ++i) {
    adj[i].clear();
    P[i] = i;
    ++mp[i];
  }
}

bool dfs(ll u, ll p, ll x) {
  bool res = 0;
  for (auto v : adj[u]) {
    if (v != p) {
      if (v != x && V.empty()) res |= dfs(v, u, x);
      else {
        if (mp.count(u)) V.push_back(u);
        return 1;
      }
    }
  }
  if (res && mp.count(u)) V.push_back(u);
  return res;
}

void Link(int A, int B) {
  if (mp.empty()) return;
  ++deg[A], ++deg[B];
  adj[A].push_back(B);
  adj[B].push_back(A);
  x = dsu(A), y = dsu(B);
  if (x == y) {
    ++cyc[x];
    ++tot;
    if (cyc[x] == 1) {
      V.clear();
      dfs(A, -1, A);
      mp.clear();
      for (auto u : V) ++mp[u];
    }
  }
  else {
    P[x] = y;
    if (cyc[x] && cyc[y]) {
      mp.clear();
      return;
    }
    cyc[y] += cyc[x];
  }
  if (deg[A] > 3) {
    if (mp.count(A)) {
      mp.clear();
      ++mp[A];
    }
    else mp.clear();
  }
  else if (deg[A] == 3) {
    V.clear();
    if (mp.count(A)) V.push_back(A);
    for (auto v : adj[A]) {
      if (mp.count(v)) V.push_back(v);
    }
    mp.clear();
    for (auto u : V) ++mp[u];
  }
  if (deg[B] > 3) {
    if (mp.count(B)) {
      mp.clear();
      ++mp[B];
    }
    else mp.clear();
  }
  else if (deg[B] == 3) {
    V.clear();
    if (mp.count(B)) V.push_back(B);
    for (auto v : adj[B]) {
      if (mp.count(v)) V.push_back(v);
    }
    mp.clear();
    for (auto u : V) ++mp[u];
  }
  if (tot > 1) {
    V.clear();
    for (auto [x, y] : mp) {
      if (deg[x] >= 3) V.push_back(x);
    }
    mp.clear();
    for (auto u : V) ++mp[u];
  }
}

int CountCritical() {
  return mp.size();
}

• Subtask 1: 20 / 20
• Subtask 2: 17 / 17
• Subtask 3: 0 / 18
• Subtask 4: 0 / 14
• Subtask 5: 0 / 31