堆排序

来源：互联网发布：淘宝店铺卖家版编辑：程序博客网时间：2024/06/18 17:10

从小到大排序，建立大根堆，每次将最后一个元素与堆顶交换，此时最大元素到堆尾，堆元素-1，自上而下维护大根堆，得到的数组即从小到大

#include<iostream>using namespace std;class Heap {private:    int *data, size;public:    Heap(int length_input) {        data = new int[length_input];        size = 0;    }    ~Heap() {        delete[] data;    }    void push(int value) {        data[size] = value;        int current = size;//子节点        int father = (current - 1) / 2;//父节点        while (data[current] > data[father]) {            swap(data[current], data[father]);            current = father;            father = (current - 1) / 2;        }        size++;    }    void output() {        for (int i = 0; i < size; i++) {            cout << data[i] << " ";        }        cout << endl;    }    int top() {         return data[0];    }    void update(int pos, int n) {//pos当前节点 n节点数        int lchild = 2 * pos + 1, rchild = 2 * pos + 2;        int max_value = pos;        if (lchild < n && data[lchild] > data[max_value]) {            max_value = lchild;        }        if (rchild < n && data[rchild] > data[max_value]) {            max_value = rchild;        }        if (max_value != pos) {            swap(data[pos], data[max_value]);            update(max_value, n);        }    }    void pop() {        swap(data[0], data[size - 1]);        size--;        update(0, size);    }    void heap_sort(){          for(int i=size-1;i>=1;i--){            swap(data[i],data[0]);             update(0, i);    }    }};int main() {    int arr[10] = { 12, 9, 30, 24, 30, 4, 55, 64, 22, 37 };    Heap heap(100);    for (int i = 0; i < 10; i++) {        heap.push(arr[i]);    }    heap.output();    heap.heap_sort();    heap.output();    return 0;}

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