• 堆的属性

1. 完全二叉树
2. 每个节点的值都大于（最大堆）或都小于（最小堆）子节点的值

堆只是一种数据的组织形式，存储结构可以用数组，在构建堆的过程中，可以使用完全二叉树的性质求父子节点的下标。

父节点的下标 = 向下取整 ( (子节点下标 - 1) /  2)

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
void minheap();
void maxheap();
using namespace std;
int arr[8] = { 53,17,78,9,45,65,87,23 };
int *a = new int[8];//保存小根堆
int index = 0;
int main()
{minheap();cout << "建立的最小堆为：" << endl;for (int i = 0; i < 8; i++){cout << a[i] <<" ";}system("pause");
}void maxheap() {while(index < 8) {a[index] = arr[index];if (index != 0) {int son_index = index;int par_index = floor((son_index - 1) / 2);while(a[par_index] < a[son_index]) {int tmp = a[par_index];a[par_index] = a[son_index];a[son_index] = tmp;son_index = par_index;par_index = floor((par_index - 1) / 2);}}index ++;}
}
void minheap()
{while (index < 8) {a[index] = arr[index];if (index != 0) {int son_index = index;int par_index = floor((son_index - 1) / 2);while (a[par_index] > a[son_index]) {//小根堆:父节点大的话需要交换int temp = a[par_index];//交换a[par_index] = a[son_index];a[son_index] = temp;son_index = par_index;//迭代看之前的是否需要调整par_index = floor((son_index - 1) / 2);}}index ++;}
}