Tifa's CP Library

:heavy_check_mark: dsu_pd (src/code/ds/dsu_pd.hpp)

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Code

#ifndef TIFALIBS_DS_DSU_PD
#define TIFALIBS_DS_DSU_PD

#include "../util/util.hpp"

namespace tifa_libs::ds {

class dsu_pd {
  vec<i32> p;
  vecp<u32, i32> edges;

 public:
  explicit constexpr dsu_pd(u32 sz) : p(sz, -1) {}

  constexpr i32 find(u32 x) { return p[x] < 0 ? (i32)x : find((u32)p[x]); }
  constexpr u32 size(u32 x) { return (u32)-p[(u32)find(x)]; }
  constexpr u32 time() { return (u32)edges.size(); }
  constexpr bool same(u32 x, u32 y) { return find(x) == find(y); }
  constexpr bool merge(u32 x, u32 y) {
    if ((x = (u32)find(x)) == (y = (u32)find(y))) return false;
    if (p[x] > p[y]) std::swap(x, y);
    edges.emplace_back(y, p[y]);
    p[x] += p[y];
    p[y] = (i32)x;
    return true;
  }
  constexpr void rollback(u32 t) {
    while (edges.size() > t) {
      auto [i, pi] = edges.back();
      edges.pop_back();
      assert(p[(u32)p[i]] < 0);
      p[(u32)p[i]] -= pi;
      p[i] = pi;
    }
  }
};

}  // namespace tifa_libs::ds

#endif
#line 1 "src/code/ds/dsu_pd.hpp"



#line 1 "src/code/util/util.hpp"



#include <bits/stdc++.h>

template <class T>
constexpr T abs(T x) { return x < 0 ? -x : x; }

using i8 = int8_t;
using i16 = int16_t;
using i32 = int32_t;
using i64 = int64_t;
using i128 = __int128_t;
using isz = ptrdiff_t;

using u8 = uint8_t;
using u16 = uint16_t;
using u32 = uint32_t;
using u64 = uint64_t;
using u128 = __uint128_t;
using usz = size_t;

using f32 = float;
using f64 = double;
using f128 = long double;

template <class T>
using ptt = std::pair<T, T>;
template <class T>
using pt3 = std::tuple<T, T, T>;
template <class T>
using pt4 = std::tuple<T, T, T, T>;

template <class T, usz N>
using arr = std::array<T, N>;
template <class T>
using vec = std::vector<T>;
template <class T>
using vvec = vec<vec<T>>;
template <class T>
using v3ec = vec<vvec<T>>;
template <class U, class T>
using vecp = vec<std::pair<U, T>>;
template <class U, class T>
using vvecp = vvec<std::pair<U, T>>;
template <class T>
using vecpt = vec<ptt<T>>;
template <class T>
using vvecpt = vvec<ptt<T>>;

template <class T, class C = std::less<T>>
using pq = std::priority_queue<T, vec<T>, C>;
template <class T>
using pqg = std::priority_queue<T, vec<T>, std::greater<T>>;

using strn = std::string;
using strnv = std::string_view;

using vecu = vec<u32>;
using vvecu = vvec<u32>;
using v3ecu = v3ec<u32>;
using vecu64 = vec<u64>;
using vecb = vec<bool>;
using vvecb = vvec<bool>;

#ifdef ONLINE_JUDGE
#undef assert
#define assert(x) 42
#endif

using namespace std::literals;

constexpr i8 operator""_i8(unsigned long long x) { return (i8)x; }
constexpr i16 operator""_i16(unsigned long long x) { return (i16)x; }
constexpr i32 operator""_i32(unsigned long long x) { return (i32)x; }
constexpr i64 operator""_i64(unsigned long long x) { return (i64)x; }
constexpr isz operator""_iz(unsigned long long x) { return (isz)x; }

constexpr u8 operator""_u8(unsigned long long x) { return (u8)x; }
constexpr u16 operator""_u16(unsigned long long x) { return (u16)x; }
constexpr u32 operator""_u32(unsigned long long x) { return (u32)x; }
constexpr u64 operator""_u64(unsigned long long x) { return (u64)x; }
constexpr usz operator""_uz(unsigned long long x) { return (usz)x; }

inline const auto fn_0 = [](auto&&...) {};


#line 5 "src/code/ds/dsu_pd.hpp"

namespace tifa_libs::ds {

class dsu_pd {
  vec<i32> p;
  vecp<u32, i32> edges;

 public:
  explicit constexpr dsu_pd(u32 sz) : p(sz, -1) {}

  constexpr i32 find(u32 x) { return p[x] < 0 ? (i32)x : find((u32)p[x]); }
  constexpr u32 size(u32 x) { return (u32)-p[(u32)find(x)]; }
  constexpr u32 time() { return (u32)edges.size(); }
  constexpr bool same(u32 x, u32 y) { return find(x) == find(y); }
  constexpr bool merge(u32 x, u32 y) {
    if ((x = (u32)find(x)) == (y = (u32)find(y))) return false;
    if (p[x] > p[y]) std::swap(x, y);
    edges.emplace_back(y, p[y]);
    p[x] += p[y];
    p[y] = (i32)x;
    return true;
  }
  constexpr void rollback(u32 t) {
    while (edges.size() > t) {
      auto [i, pi] = edges.back();
      edges.pop_back();
      assert(p[(u32)p[i]] < 0);
      p[(u32)p[i]] -= pi;
      p[i] = pi;
    }
  }
};

}  // namespace tifa_libs::ds


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