Submission #1321495

#TimeUsernameProblemLanguageResultExecution timeMemory
1321495mannshah1211Making Friends on Joitter is Fun (JOI20_joitter2)C++20
100 / 100
568 ms65268 KiB
// ロンリーガールはいつまでも
// 届かない夢見て
#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "algo/debug.h"
#else
#define debug(...) 42
#endif

class dsu {
 public:
  vector<int> p, sz;
  vector<set<int>> child, g, rev_g;
  queue<pair<int, int>> que;
  int n;
  long long ans = 0;

  dsu(int _n) : n(_n) {
    p.resize(n);
    iota(p.begin(), p.end(), 0);
    sz.resize(n);
    fill(sz.begin(), sz.end(), 1);
    child.resize(n);
    g.resize(n);
    rev_g.resize(n);
    for (int i = 0; i < n; i++) {
      child[i].insert(i);
    }
  }

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

  void add(int u, int v) {
    g[u].insert(v);
    rev_g[v].insert(u);
    if (g[v].find(u) != g[v].end()) {
      que.emplace(u, v);
    }
  }

  int siz(int x) {
    return g[x].size() + rev_g[x].size() + child[x].size();
  }

  void help(int u, int v) {
    if (u == v) {
      return;
    }
    if (siz(u) < siz(v)) {
      swap(u, v);
    }
    ans += static_cast<long long>(sz[u]) * static_cast<long long>(child[v].size()) + static_cast<long long>(sz[v]) * static_cast<long long>(child[u].size());
    p[v] = u;
    sz[u] += sz[v];
    for (int x : child[v]) {
      if (child[u].find(x) != child[u].end()) {
        ans -= sz[u];
      } else {
        child[u].insert(x);
      }
    }
    g[v].erase(u), rev_g[u].erase(v);
    g[u].erase(v), rev_g[v].erase(u);
    for (int x : g[v]) {
      rev_g[x].erase(v);
      add(u, x);
    }
    for (int x : rev_g[v]) {
      g[x].erase(v);
      add(x, u);
    }
  }

  void unite(int u, int v) {
    v = get(v);
    if (get(u) != v && child[v].find(u) == child[v].end()) {
      child[v].insert(u);
      ans += sz[v];
      u = get(u);
      add(u, v);
      while (!que.empty()) {
        auto [uu, vv] = que.front();
        que.pop();
        help(get(uu), get(vv));
      }
    }
  }
};

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr); 
  int n, m;
  cin >> n >> m;
  dsu ds(n);
  for (int i = 0; i < m; i++) {
    int u, v;
    cin >> u >> v;
    --u; --v;
    ds.unite(u, v);
    cout << ds.ans << '\n';
  }
  return 0;
}
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...