Submission #211973

#	Time	Username	Problem	Language	Result	Execution time	Memory
211973		achvanov	Making Friends on Joitter is Fun (JOI20_joitter2)	C++17	0 / 100	10 ms	12032 KiB

joitter2

#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 10;
int n, m;
long long ans;
int p[N];
vector<int> cl[N];
set<int> in[N], in2[N];

long long tot(int v) {
  return 1ll * cl[v].size() * (cl[v].size() - 1);
}

int get(int v) {
  return (v == p[v] ? v : p[v] = get(p[v]));
}

long long kek(int v) {
  return 1ll * cl[v].size() * in[v].size();
}

void unite(int u, int v) {
  u = get(u), v = get(v);
  if (u == v) {
    return;
  }
  if (cl[u].size() + in[u].size() < cl[v].size() + in[v].size()) {
    swap(u, v);
  }
  ans -= tot(u);
  ans -= tot(v);
  ans -= kek(v);
  ans -= kek(u);
  for (int x : cl[v]) {
    cl[u].push_back(x);
    if (in[u].count(x)) {
      in[u].erase(x);
    }
  }
  for (int x : in[v]) {
    if (get(x) != u) {
      in[u].insert(x);
    }
  }
  for (int x : in2[v]) {
    if (x != u) {
      in2[u].insert(x);
    }
  }
  for (int x : in[u]) {
    assert(get(x) != u);
  }
  ans += kek(u);
  ans += tot(u);
  p[v] = u;
}

void connect(int u, int v) {
  if (get(u) == get(v)) {
    return;
  }
  if (in[get(v)].count(u)) {
    return;
  }
  if (in2[get(u)].count(get(v))) {
    unite(u, v);
  } else {
    ans += cl[get(v)].size();
    in[get(v)].insert(u);
    in2[get(v)].insert(get(u));
  }
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);

  cin >> n >> m;
  for (int i = 0; i < n; ++i) {
    cl[i].push_back(i);
    p[i] = i;
  }
  while (m--) {
    int u, v;
    cin >> u >> v;
    --u, --v;
    connect(u, v);
    cout << ans << '\n';
    //cout.flush();
  }

  return 0;
}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 16
• Subtask 3: 0 / 83