tpl_sparse_table_test.cc

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/*
                          Aleph_w
 
  Data structures & Algorithms
  version 2.0.0b
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
 
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
 
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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  SOFTWARE.
*/
 
 
# include <gtest/gtest.h>
 
# include <tpl_sparse_table.H>
 
# include <algorithm>
# include <cstddef>
# include <numeric>
# include <utility>
# include <vector>
 
using namespace Aleph;
using namespace testing;
 
namespace
{
  struct Gcd_Op
  {
    int operator()(const int a, const int b) const noexcept
    {
      return std::gcd(a, b);
    }
  };
 
  template <typename T, class Op>
  T fold_range(const std::vector<T> & values,
               const size_t l, const size_t r, Op op)
  {
    T acc = values[l];
    for (size_t i = l + 1; i <= r; ++i)
      acc = op(acc, values[i]);
    return acc;
  }
 
  // A bit set whose `+` is union: idempotent, so it must stay accepted.
  struct Bits
  {
    unsigned mask = 0;
    Bits operator+(const Bits & o) const noexcept { return {mask | o.mask}; }
    bool operator==(const Bits &) const = default;
  };
 
  struct My_Sum
  {
    int operator()(const int a, const int b) const noexcept { return a + b; }
  };
 
  template <class T, class Op>
  concept buildable = requires { typename Gen_Sparse_Table<T, Op>; };
} // namespace
 
// Opt-in through the customization point.
template <>
inline constexpr bool Aleph::is_known_non_idempotent_op<My_Sum, int> = true;
 
// Known non-idempotent functors are rejected at compile time: a sum table
// used to compile and answer query(0, 4) over {1..5} with 24 instead of 15.
static_assert(not buildable<int, std::plus<int>> and not buildable<int, std::plus<>>);
static_assert(not buildable<long, Aleph::plus<long>> and not buildable<double, std::multiplies<double>>);
static_assert(not buildable<int, std::minus<int>> and not buildable<unsigned, std::bit_xor<unsigned>>);
static_assert(not buildable<int, Aleph::modulus<int>> and not buildable<int, My_Sum>);
static_assert(not SparseTableOp<std::plus<int>, int>);
 
// Everything else passes, as before.
static_assert(buildable<int, Min_Op<int>> and buildable<int, Max_Op<int>> and buildable<int, Gcd_Op>);
static_assert(buildable<int, std::bit_and<int>> and buildable<int, std::bit_or<>>);
static_assert(buildable<bool, std::plus<bool>> and buildable<Bits, std::plus<Bits>>);
constexpr auto min_lambda = [](const int a, const int b) { return std::min(a, b); };
static_assert(IdempotentOp<decltype(min_lambda), int>);
 
TEST(SparseTable, EmptyConstructionAndErrors)
{
  Sparse_Table<int> st(std::vector<int>{});
 
  EXPECT_TRUE(st.is_empty());
  EXPECT_EQ(st.size(), 0U);
  EXPECT_EQ(st.num_levels(), 0U);
 
  EXPECT_THROW(st.get(0), std::out_of_range);
  EXPECT_THROW(st.query(0, 0), std::out_of_range);
}
 
TEST(SparseTable, UniformValueConstruction)
{
  Gen_Sparse_Table<int, Min_Op<int>> st(16, 7);
 
  EXPECT_EQ(st.size(), 16U);
  EXPECT_FALSE(st.is_empty());
  EXPECT_EQ(st.query(0, 15), 7);
  EXPECT_EQ(st.query(5, 11), 7);
 
  for (size_t i = 0; i < st.size(); ++i)
    EXPECT_EQ(st.get(i), 7);
}
 
TEST(SparseTable, MinAndMaxAgainstBruteForce)
{
  const std::vector<int> values = {9, 4, 7, 1, 8, 2, 6, 3, 5, 0};
  Sparse_Table<int> mn(values);
  Max_Sparse_Table<int> mx(values);
 
  for (size_t l = 0; l < values.size(); ++l)
    for (size_t r = l; r < values.size(); ++r)
      {
        const int expected_min = *std::min_element(values.begin() + l,
                                                   values.begin() + r + 1);
        const int expected_max = *std::max_element(values.begin() + l,
                                                   values.begin() + r + 1);
        EXPECT_EQ(mn.query(l, r), expected_min);
        EXPECT_EQ(mx.query(l, r), expected_max);
      }
}
 
TEST(SparseTable, ConstructorsFromAllContainers)
{
  const std::vector<int> values = {5, 3, 7, 1, 9, 2, 8, 4, 6};
  Sparse_Table<int> from_vector(values);
 
  Array<int> arr;
  for (const int x : values)
    arr.append(x);
  Sparse_Table<int> from_array(arr);
 
  DynList<int> list;
  for (const int x : values)
    list.append(x);
  Sparse_Table<int> from_list(list);
 
  Sparse_Table<int> from_init = {5, 3, 7, 1, 9, 2, 8, 4, 6};
 
  for (size_t l = 0; l < values.size(); ++l)
    for (size_t r = l; r < values.size(); ++r)
      {
        const int expected = *std::min_element(values.begin() + l,
                                               values.begin() + r + 1);
        EXPECT_EQ(from_vector.query(l, r), expected);
        EXPECT_EQ(from_array.query(l, r), expected);
        EXPECT_EQ(from_list.query(l, r), expected);
        EXPECT_EQ(from_init.query(l, r), expected);
      }
}
 
TEST(SparseTable, CustomAssociativeIdempotentOperation)
{
  const std::vector<int> values = {12, 18, 24, 36, 60, 48, 30, 90, 15, 45};
  Gen_Sparse_Table<int, Gcd_Op> st(values, Gcd_Op{});
 
  for (size_t l = 0; l < values.size(); ++l)
    for (size_t r = l; r < values.size(); ++r)
      EXPECT_EQ(st.query(l, r), fold_range(values, l, r, Gcd_Op{}));
}
 
TEST(SparseTable, ClassTypePlusStillAccepted)
{
  const std::vector<Bits> values = {{1}, {2}, {4}, {8}, {16}};
  Gen_Sparse_Table<Bits, std::plus<Bits>> st(values);
 
  for (size_t l = 0; l < values.size(); ++l)
    for (size_t r = l; r < values.size(); ++r)
      EXPECT_EQ(st.query(l, r), fold_range(values, l, r, std::plus<Bits>{}));
}
 
TEST(SparseTable, ValuesCopyMoveAndSwap)
{
  const std::vector<int> base = {8, 6, 7, 5, 3, 0, 9};
  Sparse_Table<int> st(base);
 
  Array<int> vals = st.values();
  ASSERT_EQ(vals.size(), base.size());
  for (size_t i = 0; i < base.size(); ++i)
    EXPECT_EQ(vals(i), base[i]);
 
  Sparse_Table<int> copy = st;
  EXPECT_EQ(copy.query(1, 5), 0);
 
  Sparse_Table<int> moved = std::move(copy);
  EXPECT_EQ(moved.query(2, 6), 0);
 
  Sparse_Table<int> other = {100, 50, 75};
  moved.swap(other);
 
  EXPECT_EQ(moved.size(), 3U);
  EXPECT_EQ(moved.query(0, 2), 50);
  EXPECT_EQ(other.size(), base.size());
  EXPECT_EQ(other.query(0, 6), 0);
}
 
TEST(SparseTable, BoundsChecking)
{
  Sparse_Table<int> st = {1, 2, 3};
 
  EXPECT_THROW(st.get(3), std::out_of_range);
  EXPECT_THROW(st.query(0, 3), std::out_of_range);
  EXPECT_THROW(st.query(2, 1), std::out_of_range);
}