79 lines
3.0 KiB
C++
79 lines
3.0 KiB
C++
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// fig14_15.cpp
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// Algorithms make_heap, sort_heap, push_heap and pop_heap.
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#include <iostream>
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#include <algorithm>
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#include <array>
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#include <vector>
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#include <iterator>
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int main() {
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std::ostream_iterator<int> output{std::cout, " "};
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std::array heapArray{3, 100, 52, 77, 22, 31, 1, 98, 13, 40};
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std::cout << "heapArray before make_heap:\n";
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std::ranges::copy(heapArray, output);
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std::ranges::make_heap(heapArray); // create heap from heapArray
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std::cout << "\nheapArray after make_heap:\n";
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std::ranges::copy(heapArray, output);
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std::ranges::sort_heap(heapArray); // sort elements with sort_heap
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std::cout << "\nheapArray after sort_heap:\n";
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std::ranges::copy(heapArray, output);
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// lambda to add an int to a heap
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auto push{
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[&](std::vector<int>& heap, int value) {
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std::cout << "\n\npushing " << value << " onto heap";
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heap.push_back(value); // add value to the heap
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std::ranges::push_heap(heap); // insert last element into heap
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std::cout << "\nheap: ";
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std::ranges::copy(heap, output);
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}
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};
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// lambda to remove an item from the heap
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auto pop{
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[&](std::vector<int>& heap) {
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std::ranges::pop_heap(heap); // remove max item from heap
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std::cout << "\n\npopping highest priority item: " << heap.back();
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heap.pop_back(); // remove vector's last element
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std::cout << "\nheap: ";
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std::ranges::copy(heap, output);
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}
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};
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std::vector<int> heapVector{};
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// place five integers into heapVector, maintaining it as a heap
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for (auto value : {3, 52, 100}) {
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push(heapVector, value);
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}
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pop(heapVector); // remove max item
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push(heapVector, 22); // add new item to heap
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pop(heapVector); // remove max item
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push(heapVector, 77); // add new item to heap
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pop(heapVector); // remove max item
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pop(heapVector); // remove max item
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pop(heapVector); // remove max item
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std::cout << "\n";
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}
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/**************************************************************************
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* (C) Copyright 1992-2021 by Deitel & Associates, Inc. and *
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* Pearson Education, Inc. All Rights Reserved. *
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* *
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* DISCLAIMER: The authors and publisher of this book have used their *
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* best efforts in preparing the book. These efforts include the *
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* development, research, and testing of the theories and programs *
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* to determine their effectiveness. The authors and publisher make *
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* no warranty of any kind, expressed or implied, with regard to these *
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* programs or to the documentation contained in these books. The authors *
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* and publisher shall not be liable in any event for incidental or *
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* consequential damages in connection with, or arising out of, the *
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* furnishing, performance, or use of these programs. *
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**************************************************************************/
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