ds/potential_dsu.hpp

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• Last update: 2024-11-09 00:49:07+00:00
• Include: #include "ds/potential_dsu.hpp"

Depends on

• prelude.hpp

Code

#pragma once
#include "prelude.hpp"

template <class T>
class potential_dsu {
 public:
  potential_dsu(int n) : par(n, -1), f(n), cnt(n) {}
  int count() const { return cnt; }
  void clear() {
    fill(par.begin(), par.end(), -1);
    cnt = par.size();
  }
  int find(int x) {
    if (par[x] < 0) return x;
    int r = find(par[x]);
    f[x] += f[par[x]];
    return par[x] = r;
  }
  bool same(int x, int y) { return find(x) == find(y); }
  T phi(int x) { return find(x), f[x]; }
  // phi(x) + d = phi(y)
  // Returns false on failure
  bool unite(int x, int y, T d) {
    d += phi(x), x = find(x);
    d -= phi(y), y = find(y);
    if (x == y) return d != T(0);
    if (par[x] > par[y]) swap(x, y), d = -d;
    par[x] += par[y], par[y] = x, f[y] = d;
    cnt--;
    return false;
  }
  int size(int x) { return -par[find(x)]; }
  vector<vector<int>> groups() {
    vector<vector<int>> res(par.size());
    for (int x = 0; x < par.size(); x++) res[find(x)].push_back(x);
    res.erase(remove_if(all(res), [](const auto& v) { return v.empty(); }),
              res.end());
    return res;
  }

 private:
  vector<int> par;
  vector<T> f;  // f(x) - f(par(x))
  int cnt;
};

#line 2 "prelude.hpp"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
using vc = vector<char>;
#define rep2(i, m, n) for (auto i = (m); i < (n); i++)
#define rep(i, n) rep2(i, 0, n)
#define repr2(i, m, n) for (auto i = (n); i-- > (m);)
#define repr(i, n) repr2(i, 0, n)
#define all(x) begin(x), end(x)
auto ndvec(int n, auto e) { return vector(n, e); }
auto ndvec(int n, auto ...e) { return vector(n, ndvec(e...)); }
auto comp_key(auto&& f) { return [&](auto&& a, auto&& b) { return f(a) < f(b); }; }
auto& max(const auto& a, const auto& b) { return a < b ? b : a; }
auto& min(const auto& a, const auto& b) { return b < a ? b : a; }
#if __cpp_lib_ranges
namespace R = std::ranges;
namespace V = std::views;
#endif
#line 3 "ds/potential_dsu.hpp"

template <class T>
class potential_dsu {
 public:
  potential_dsu(int n) : par(n, -1), f(n), cnt(n) {}
  int count() const { return cnt; }
  void clear() {
    fill(par.begin(), par.end(), -1);
    cnt = par.size();
  }
  int find(int x) {
    if (par[x] < 0) return x;
    int r = find(par[x]);
    f[x] += f[par[x]];
    return par[x] = r;
  }
  bool same(int x, int y) { return find(x) == find(y); }
  T phi(int x) { return find(x), f[x]; }
  // phi(x) + d = phi(y)
  // Returns false on failure
  bool unite(int x, int y, T d) {
    d += phi(x), x = find(x);
    d -= phi(y), y = find(y);
    if (x == y) return d != T(0);
    if (par[x] > par[y]) swap(x, y), d = -d;
    par[x] += par[y], par[y] = x, f[y] = d;
    cnt--;
    return false;
  }
  int size(int x) { return -par[find(x)]; }
  vector<vector<int>> groups() {
    vector<vector<int>> res(par.size());
    for (int x = 0; x < par.size(); x++) res[find(x)].push_back(x);
    res.erase(remove_if(all(res), [](const auto& v) { return v.empty(); }),
              res.end());
    return res;
  }

 private:
  vector<int> par;
  vector<T> f;  // f(x) - f(par(x))
  int cnt;
};

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