Breaking News: Grepper is joining You.com. Read the official announcement!

implement a priority queue in c++ using heap data structure. Use generics so that it can support all data types like actual priority_queue in c++

Quaint Quetzal answered on August 31, 2023 Popularity 2/10 Helpfulness 1/10

answer implement a priority queue in c++ using heap data structure. Use generics so that it can support all data types like actual priority_queue in c++

implement a priority queue in c++ using heap data structure. Use generics so that it can support all data types like actual priority_queue in c++

Comment

#include <iostream>
#include <vector>
#include <functional> // For std::less (default comparator)

template <typename T, typename Compare = std::less<T>>
class PriorityQueue {
private:
    std::vector<T> heap;
    Compare compare;

    void heapifyUp(int index) {
        while (index > 0) {
            int parent = (index - 1) / 2;
            if (compare(heap[parent], heap[index]))
                break;
            std::swap(heap[parent], heap[index]);
            index = parent;
        }
    }

    void heapifyDown(int index) {
        int left = 2 * index + 1;
        int right = 2 * index + 2;
        int smallest = index;

        if (left < heap.size() && compare(heap[left], heap[smallest]))
            smallest = left;
        if (right < heap.size() && compare(heap[right], heap[smallest]))
            smallest = right;

        if (smallest != index) {
            std::swap(heap[index], heap[smallest]);
            heapifyDown(smallest);
        }
    }

public:
    bool empty() const {
        return heap.empty();
    }

    size_t size() const {
        return heap.size();
    }

    const T& top() const {
        if (empty())
            throw std::out_of_range("PriorityQueue is empty");
        return heap[0];
    }

    void push(const T& value) {
        heap.push_back(value);
        heapifyUp(heap.size() - 1);
    }

    void pop() {
        if (empty())
            throw std::out_of_range("PriorityQueue is empty");
        heap[0] = heap.back();
        heap.pop_back();
        heapifyDown(0);
    }
};

int main() {
    // Example usage
    PriorityQueue<int> pq;

    pq.push(10);
    pq.push(5);
    pq.push(20);

    while (!pq.empty()) {
        std::cout << pq.top() << " ";
        pq.pop();
    }

    return 0;
}

Popularity 2/10 Helpfulness 1/10 Language cpp

Source: chat.openai.com

Tags: c++ generics heap priority-queue types using

Link to this answer
Share Copy Link

Contributed on Aug 31 2023

Quaint Quetzal

0 Answers Avg Quality 2/10

implement a priority queue in c++ using heap data structure. Use generics so that it can support all data types like actual priority_queue in c++

Contents

More Related Answers

implement a priority queue in c++ using heap data structure. Use generics so that it can support all data types like actual priority_queue in c++

Grepper

Documentation

Social

Legal

Contact

Oops, You will need to install Grepper and log-in to perform this action.