binheap.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
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  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 <algorithm>
#include <functional>
#include <numeric>
#include <random>
#include <vector>
 
#include <gtest/gtest.h>
 
#include <tpl_dynBinHeap.H>
 
using namespace Aleph;
 
TEST(DynBinHeapTest, InsertExtractInOrder)
{
  DynBinHeap<int> heap;
  const std::vector<int> values = {7, 3, 11, 0, 5, 9, 1};
 
  for (const int v : values)
    heap.insert(v);
 
  std::vector<int> expected = values;
  std::sort(expected.begin(), expected.end());
 
  for (const int v : expected)
    {
      ASSERT_EQ(heap.top(), v);
      EXPECT_EQ(heap.getMin(), v);
    }
 
  EXPECT_TRUE(heap.is_empty());
  EXPECT_EQ(heap.size(), 0u);
}
 
TEST(DynBinHeapTest, RemoveArbitraryNodes)
{
  DynBinHeap<int> heap;
  const std::vector<int> values = {40, 10, 30, 20, 50, 60, 70, 15};
  std::vector<std::reference_wrapper<int>> refs;
  refs.reserve(values.size());
 
  for (const int v : values)
    refs.emplace_back(heap.insert(v));
 
  ASSERT_EQ(heap.size(), values.size());
 
  heap.remove(refs[3]);  // remove an interior node
  heap.remove(refs.back()); // remove what used to be the last inserted node
 
  std::vector<int> remaining;
  while (!heap.is_empty())
    remaining.push_back(heap.getMin());
 
  std::vector<int> expected = values;
  const auto erase_value = [&expected](int needle) {
    const auto it = std::find(expected.begin(), expected.end(), needle);
    ASSERT_NE(it, expected.end());
    expected.erase(it);
  };
  erase_value(20);
  erase_value(15);
  std::sort(expected.begin(), expected.end());
 
  EXPECT_EQ(remaining, expected);
}
 
TEST(DynBinHeapTest, UpdateReordersAfterPriorityChange)
{
  DynBinHeap<int> heap;
  auto &high = heap.insert(50);
  auto &low = heap.insert(5);
  heap.insert(20);
 
  high = 1; // becomes the best priority
  heap.update(high);
  EXPECT_EQ(heap.top(), 1);
 
  low = 60; // now should sink
  heap.update(low);
 
  std::vector<int> drained;
  while (!heap.is_empty())
    drained.push_back(heap.getMin());
 
  EXPECT_EQ(drained, std::vector<int>({1, 20, 60}));
}
 
TEST(DynBinHeapTest, RandomizedInsertExtract)
{
  DynBinHeap<int> heap;
  std::vector<int> values(200);
  std::iota(values.begin(), values.end(), -100);
  std::mt19937 rng(42);
  std::shuffle(values.begin(), values.end(), rng);
 
  for (int v : values)
    heap.insert(v);
 
  std::vector<int> extracted;
  while (!heap.is_empty())
    extracted.push_back(heap.getMin());
 
  std::vector<int> expected = values;
  std::sort(expected.begin(), expected.end());
  EXPECT_EQ(extracted, expected);
}
 
TEST(DynBinHeapTest, IteratorTraversesAllElements)
{
  DynBinHeap<int> heap;
  constexpr size_t N = 64;
  for (size_t i = 0; i < N; ++i)
    heap.insert(static_cast<int>(i));
 
  size_t count = 0;
  for (auto it = heap.get_it(); it.has_curr(); it.next())
    ++count;
 
  EXPECT_EQ(count, N);
}
 
TEST(DynBinHeapTest, EmptyRemovesAllNodes)
{
  DynBinHeap<int> heap;
  for (int i = 0; i < 50; ++i)
    heap.insert(i);
 
  heap.empty();
  EXPECT_TRUE(heap.is_empty());
  EXPECT_EQ(heap.size(), 0u);
 
  // Verify heap can be reused after empty
  heap.insert(10);
  EXPECT_EQ(heap.getMin(), 10);
  EXPECT_TRUE(heap.is_empty());
}
 
TEST(DynBinHeapTest, UpdateWithDuplicatePriorities)
{
  DynBinHeap<int> heap;
  std::vector<std::reference_wrapper<int>> refs;
  for (int i = 0; i < 5; ++i)
    refs.emplace_back(heap.insert(10)); // duplicates
 
  // Make one element the new minimum
  refs.front().get() = -1;
  heap.update(refs.front());
  EXPECT_EQ(heap.top(), -1);
 
  // Make another element very large to ensure sift-down works
  refs.back().get() = 100;
  heap.update(refs.back());
 
  std::vector<int> drained;
  while (!heap.is_empty())
    drained.push_back(heap.getMin());
 
  EXPECT_TRUE(std::is_sorted(drained.begin(), drained.end()));
  EXPECT_EQ(drained.front(), -1);
  EXPECT_EQ(drained.back(), 100);
}