ds/hashmap.hpp

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• Last update: 2023-11-21 19:08:32+09:00
• Include: #include "ds/hashmap.hpp"

Required by

• ds/static_range_frequency.hpp
• ds/to_small_key.hpp
• geo/closest_pair.hpp
• geo/range_closest_pair_query.hpp
• graph/eulerwalk.hpp
• graph/vs_to_es.hpp
• mod/mod_kth_root.hpp
• mod/mod_log.hpp
• nt/discrete_log.hpp
• other/connected_dp.hpp

Verified with

• test/aoj/CGL_5_A.test.cpp
• test/library_checker/datastructure/associative_array_hashmap.test.cpp
• test/library_checker/datastructure/set_xor_min.test.cpp
• test/library_checker/datastructure/static_range_freq.test.cpp
• test/library_checker/math/discrete_logarithm_mod.test.cpp
• test/library_checker/math/kth_root_mod.test.cpp
• test/mytest/range_closest_pair.test.cpp
• test/mytest/tdpc_grid_dp.test.cpp
• test/yukicoder/1339.test.cpp
• test/yukicoder/1383.test.cpp
• test/yukicoder/1397.test.cpp
• test/yukicoder/1561.test.cpp
• test/yukicoder/1634.test.cpp
• test/yukicoder/1726.test.cpp
• test/yukicoder/1769.test.cpp
• test/yukicoder/1881.test.cpp
• test/yukicoder/2102.test.cpp
• test/yukicoder/2167.test.cpp
• test/yukicoder/263.test.cpp
• test/yukicoder/541.test.cpp
• test/yukicoder/578.test.cpp
• test/yukicoder/579.test.cpp
• test_atcoder/abc220g.test.cpp
• test_atcoder/abc222g.test.cpp
• test_atcoder/abc227g.test.cpp
• test_atcoder/abc270_g.test.cpp
• test_atcoder/abc273_e.test.cpp
• test_atcoder/arc157a.test.cpp

Code

#pragma once

// u64 -> Val

template <typename Val, int LOG = 20, bool KEEP_IDS = false>
struct HashMap {
  static constexpr int N = (1 << LOG);
  u64* key;
  Val* val;
  vc<int> IDS;
  bitset<N> used;
  const int shift;
  const u64 r = 11995408973635179863ULL;
  HashMap() : key(new u64[N]), val(new Val[N]), shift(64 - LOG) {}
  u32 hash(u64 x) {
    static const u64 FIXED_RANDOM
        = std::chrono::steady_clock::now().time_since_epoch().count();
    return (u64(x + FIXED_RANDOM) * r) >> shift;
  }

  int index(const u64& k) {
    int i = 0;
    for (i = hash(k); used[i] && key[i] != k; (i += 1) &= (N - 1)) {}
    return i;
  }

  Val& operator[](const u64& k) {
    int i = index(k);
    if (!used[i]) {
      used[i] = 1, key[i] = k, val[i] = Val{};
      if constexpr (KEEP_IDS) IDS.eb(i);
    }
    return val[i];
  }

  Val get(const u64& k, Val default_value) {
    int i = index(k);
    if (!used[i]) return default_value;
    return val[i];
  }

  bool count(const u64& k) {
    int i = index(k);
    return used[i] && key[i] == k;
  }

  void reset() {
    static_assert(KEEP_IDS);
    for (auto&& i: IDS) used[i] = 0;
    IDS.clear();
  }

  // f(key, val)

  template <typename F>
  void enumerate_all(F f) {
    static_assert(KEEP_IDS);
    for (auto&& i: IDS) f(key[i], val[i]);
  }
};

#line 2 "ds/hashmap.hpp"

// u64 -> Val

template <typename Val, int LOG = 20, bool KEEP_IDS = false>
struct HashMap {
  static constexpr int N = (1 << LOG);
  u64* key;
  Val* val;
  vc<int> IDS;
  bitset<N> used;
  const int shift;
  const u64 r = 11995408973635179863ULL;
  HashMap() : key(new u64[N]), val(new Val[N]), shift(64 - LOG) {}
  u32 hash(u64 x) {
    static const u64 FIXED_RANDOM
        = std::chrono::steady_clock::now().time_since_epoch().count();
    return (u64(x + FIXED_RANDOM) * r) >> shift;
  }

  int index(const u64& k) {
    int i = 0;
    for (i = hash(k); used[i] && key[i] != k; (i += 1) &= (N - 1)) {}
    return i;
  }

  Val& operator[](const u64& k) {
    int i = index(k);
    if (!used[i]) {
      used[i] = 1, key[i] = k, val[i] = Val{};
      if constexpr (KEEP_IDS) IDS.eb(i);
    }
    return val[i];
  }

  Val get(const u64& k, Val default_value) {
    int i = index(k);
    if (!used[i]) return default_value;
    return val[i];
  }

  bool count(const u64& k) {
    int i = index(k);
    return used[i] && key[i] == k;
  }

  void reset() {
    static_assert(KEEP_IDS);
    for (auto&& i: IDS) used[i] = 0;
    IDS.clear();
  }

  // f(key, val)

  template <typename F>
  void enumerate_all(F f) {
    static_assert(KEEP_IDS);
    for (auto&& i: IDS) f(key[i], val[i]);
  }
};

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