cpp-algo-cases/chapter_heap/my_heap.cpp

/**
 * File: my_heap.cpp
 * Created Time: 2023-02-04
 * Author: LoneRanger (836253168@qq.com), what-is-me (whatisme@outlook.jp)
 */

#include "../utils/common.hpp"

/* <20>󶥶<EFBFBD> */
class MaxHeap {
  private:
    // ʹ<>ö<EFBFBD>̬<EFBFBD><CCAC><EFBFBD>飬<EFBFBD><E9A3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>뿼<EFBFBD><EBBFBC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    vector<int> maxHeap;

    /* <20><>ȡ<EFBFBD><C8A1><EFBFBD>ӽڵ<D3BD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
    int left(int i) {
        return 2 * i + 1;
    }

    /* <20><>ȡ<EFBFBD><C8A1><EFBFBD>ӽڵ<D3BD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
    int right(int i) {
        return 2 * i + 2;
    }

    /* <20><>ȡ<EFBFBD><C8A1><EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
    int parent(int i) {
        return (i - 1) / 2; // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    }

    /* <20>ӽڵ<D3BD> i <20><>ʼ<EFBFBD><CABC><EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѻ<EFBFBD> */
    void siftUp(int i) {
        while (true) {
            // <20><>ȡ<EFBFBD>ڵ<EFBFBD> i <20>ĸ<EFBFBD><C4B8>ڵ<EFBFBD>
            int p = parent(i);
            // <20><><EFBFBD><EFBFBD>Խ<EFBFBD><D4BD><EFBFBD><EFBFBD><EFBFBD>ڵ㡱<DAB5>򡰽ڵ<F2A1B0BD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>޸<EFBFBD><DEB8><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѻ<EFBFBD>
            if (p < 0 || maxHeap[i] <= maxHeap[p])
                break;
            // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD>
            swap(maxHeap[i], maxHeap[p]);
            // ѭ<><D1AD><EFBFBD><EFBFBD><EFBFBD>϶ѻ<CFB6>
            i = p;
        }
    }

    /* <20>ӽڵ<D3BD> i <20><>ʼ<EFBFBD><CABC><EFBFBD>Ӷ<EFBFBD><D3B6><EFBFBD><EFBFBD>׶ѻ<D7B6> */
    void siftDown(int i) {
        while (true) {
            // <20>жϽڵ<CFBD> i, l, r <20><>ֵ<EFBFBD><D6B5><EFBFBD><EFBFBD><EFBFBD>Ľڵ㣬<DAB5><E3A3AC>Ϊ ma
            int l = left(i), r = right(i), ma = i;
            if (l < size() && maxHeap[l] > maxHeap[ma])
                ma = l;
            if (r < size() && maxHeap[r] > maxHeap[ma])
                ma = r;
            // <20><><EFBFBD>ڵ<EFBFBD> i <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> l, r Խ<>磬<EFBFBD><E7A3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѻ<EFBFBD><D1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
            if (ma == i)
                break;
            swap(maxHeap[i], maxHeap[ma]);
            // ѭ<><D1AD><EFBFBD><EFBFBD><EFBFBD>¶ѻ<C2B6>
            i = ma;
        }
    }

  public:
    /* <20><><EFBFBD>췽<EFBFBD><ECB7BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>б<EFBFBD><D0B1><EFBFBD><EFBFBD><EFBFBD> */
    MaxHeap(vector<int> nums) {
        // <20><><EFBFBD>б<EFBFBD>Ԫ<EFBFBD><D4AA>ԭ<EFBFBD>ⲻ<EFBFBD><E2B2BB><EFBFBD><EFBFBD><EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD>
        maxHeap = nums;
        // <20>ѻ<EFBFBD><D1BB><EFBFBD>Ҷ<EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>нڵ<D0BD>
        for (int i = parent(size() - 1); i >= 0; i--) {
            siftDown(i);
        }
    }

    /* <20><>ȡ<EFBFBD>Ѵ<EFBFBD>С */
    int size() {
        return maxHeap.size();
    }

    /* <20>ж϶<D0B6><CFB6>Ƿ<EFBFBD>Ϊ<EFBFBD><CEAA> */
    bool isEmpty() {
        return size() == 0;
    }

    /* <20><><EFBFBD>ʶѶ<CAB6>Ԫ<EFBFBD><D4AA> */
    int peek() {
        return maxHeap[0];
    }

    /* Ԫ<><D4AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
    void push(int val) {
        // <20><><EFBFBD>ӽڵ<D3BD>
        maxHeap.push_back(val);
        // <20>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѻ<EFBFBD>
        siftUp(size() - 1);
    }

    /* Ԫ<>س<EFBFBD><D8B3><EFBFBD> */
    void pop() {
        // <20>пմ<D0BF><D5B4><EFBFBD>
        if (isEmpty()) {
            throw out_of_range("<EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD>");
        }
        // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҷ<EFBFBD>ڵ㣨<DAB5><E3A3A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA><EFBFBD><EFBFBD>βԪ<CEB2>أ<EFBFBD>
        swap(maxHeap[0], maxHeap[size() - 1]);
        // ɾ<><C9BE><EFBFBD>ڵ<EFBFBD>
        maxHeap.pop_back();
        // <20>Ӷ<EFBFBD><D3B6><EFBFBD><EFBFBD>׶ѻ<D7B6>
        siftDown(0);
    }

    /* <20><>ӡ<EFBFBD>ѣ<EFBFBD><D1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>*/
    void print() {
        cout << "<EFBFBD>ѵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʾ<EFBFBD><EFBFBD>";
        printVector(maxHeap);
        cout << "<EFBFBD>ѵ<EFBFBD><EFBFBD><EFBFBD>״<EFBFBD><EFBFBD>ʾ<EFBFBD><EFBFBD>" << endl;
        TreeNode *root = vectorToTree(maxHeap);
        printTree(root);
        freeMemoryTree(root);
    }
};

/* Driver Code */
int main() {
    /* <20><>ʼ<EFBFBD><CABC><EFBFBD>󶥶<EFBFBD> */
    vector<int> vec{9, 8, 6, 6, 7, 5, 2, 1, 4, 3, 6, 2};
    MaxHeap maxHeap(vec);
    cout << "\n<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>б<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ѻ<EFBFBD>" << endl;
    maxHeap.print();

    /* <20><>ȡ<EFBFBD>Ѷ<EFBFBD>Ԫ<EFBFBD><D4AA> */
    int peek = maxHeap.peek();
    cout << "\n<EFBFBD>Ѷ<EFBFBD>Ԫ<EFBFBD><EFBFBD>Ϊ " << peek << endl;

    /* Ԫ<><D4AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
    int val = 7;
    maxHeap.push(val);
    cout << "\nԪ<EFBFBD><EFBFBD> " << val << " <20><><EFBFBD>Ѻ<EFBFBD>" << endl;
    maxHeap.print();

    /* <20>Ѷ<EFBFBD>Ԫ<EFBFBD>س<EFBFBD><D8B3><EFBFBD> */
    peek = maxHeap.peek();
    maxHeap.pop();
    cout << "\n<EFBFBD>Ѷ<EFBFBD>Ԫ<EFBFBD><EFBFBD> " << peek << " <20><><EFBFBD>Ѻ<EFBFBD>" << endl;
    maxHeap.print();

    /* <20><>ȡ<EFBFBD>Ѵ<EFBFBD>С */
    int size = maxHeap.size();
    cout << "\n<EFBFBD><EFBFBD>Ԫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ " << size << endl;

    /* <20>ж϶<D0B6><CFB6>Ƿ<EFBFBD>Ϊ<EFBFBD><CEAA> */
    bool isEmpty = maxHeap.isEmpty();
    cout << "\n<EFBFBD><EFBFBD><EFBFBD>Ƿ<EFBFBD>Ϊ<EFBFBD><EFBFBD> " << isEmpty << endl;

    return 0;
}