Tifa's CP Library

:heavy_check_mark: dinic (src/code/graph/dinic.hpp)

Depends on

Required by

Verified with

Code

#ifndef TIFALIBS_GRAPH_DINIC
#define TIFALIBS_GRAPH_DINIC

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

namespace tifa_libs::graph {

template <class EW = u32>
class dinic {
  struct YYZ {
    u32 to;
    EW w;
    u32 inv;
  };
  const u32 N;

 public:
  vvec<YYZ> e;
  vecu dep, cur;

  constexpr dinic(u32 n) : N(n), e(n) {}

  constexpr ptt<u32> add(u32 u, u32 v, EW w, EW rw = 0) {
    u32 lstu = (u32)e[u].size(), lstv = (u32)e[v].size();
    e[u].push_back({v, w, lstv}), e[v].push_back({u, rw, lstu});
    return {u, e[u].size() - 1};
  }
  u64 operator()(u32 s, u32 t) {
    u64 ret = 0, flow;
    while (bfs(s, t))
      while ((flow = dfs(s, t))) ret += flow;
    return ret;
  }

 private:
  bool bfs(u32 s, u32 t) {
    dep = vecu(N, 0);
    std::queue<u32> q;
    dep[s] = 1, q.push(s);
    while (!q.empty()) {
      u32 u = q.front();
      q.pop();
      for (auto v : e[u])
        if (!dep[v.to] && v.w) dep[v.to] = dep[u] + 1, q.push(v.to);
    }
    cur = vecu(N, 0);
    return dep[t];
  }
  constexpr u64 dfs(u32 u, u32 t, EW lim = std::numeric_limits<EW>::max()) {
    if (u == t || lim == 0) return lim;
    u64 ret = 0;
    for (u32& i = cur[u]; i < e[u].size(); ++i) {
      auto v = e[u][i];
      if (dep[v.to] == dep[u] + 1 && v.w) {
        u64 flow = dfs(v.to, t, std::min(v.w, lim));
        if (flow) {
          e[u][i].w -= flow;
          e[v.to][e[u][i].inv].w += flow;
          ret += flow, lim -= flow;
          if (!lim) break;
        } else dep[v.to] = 0;
      }
    }
    return ret;
  }
};

}  // namespace tifa_libs::graph

#endif
#line 1 "src/code/graph/dinic.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/graph/dinic.hpp"

namespace tifa_libs::graph {

template <class EW = u32>
class dinic {
  struct YYZ {
    u32 to;
    EW w;
    u32 inv;
  };
  const u32 N;

 public:
  vvec<YYZ> e;
  vecu dep, cur;

  constexpr dinic(u32 n) : N(n), e(n) {}

  constexpr ptt<u32> add(u32 u, u32 v, EW w, EW rw = 0) {
    u32 lstu = (u32)e[u].size(), lstv = (u32)e[v].size();
    e[u].push_back({v, w, lstv}), e[v].push_back({u, rw, lstu});
    return {u, e[u].size() - 1};
  }
  u64 operator()(u32 s, u32 t) {
    u64 ret = 0, flow;
    while (bfs(s, t))
      while ((flow = dfs(s, t))) ret += flow;
    return ret;
  }

 private:
  bool bfs(u32 s, u32 t) {
    dep = vecu(N, 0);
    std::queue<u32> q;
    dep[s] = 1, q.push(s);
    while (!q.empty()) {
      u32 u = q.front();
      q.pop();
      for (auto v : e[u])
        if (!dep[v.to] && v.w) dep[v.to] = dep[u] + 1, q.push(v.to);
    }
    cur = vecu(N, 0);
    return dep[t];
  }
  constexpr u64 dfs(u32 u, u32 t, EW lim = std::numeric_limits<EW>::max()) {
    if (u == t || lim == 0) return lim;
    u64 ret = 0;
    for (u32& i = cur[u]; i < e[u].size(); ++i) {
      auto v = e[u][i];
      if (dep[v.to] == dep[u] + 1 && v.w) {
        u64 flow = dfs(v.to, t, std::min(v.w, lim));
        if (flow) {
          e[u][i].w -= flow;
          e[v.to][e[u][i].inv].w += flow;
          ret += flow, lim -= flow;
          if (!lim) break;
        } else dep[v.to] = 0;
      }
    }
    return ret;
  }
};

}  // namespace tifa_libs::graph


Back to top page