堆排序

#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;
int father = (current - 1) / 2;
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) {
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(){
//堆顶每次都为当前堆的最值，挑出堆顶元素
//放入堆的最末尾（与末尾元素交换）
//原本末尾元素作为临时堆顶，原堆顶元素相当于被挑出来的当前堆最值
//再对挑出最值得新堆进行下一个最值的寻找，
//即调整新堆，找出新堆堆顶
for(int i=size-1;i>=1;i--){
//如果循环到0，就是自己和自己交换
swap(data[i],data[0]);
//最值被选出到i位置

//挑出最值后，更新剩下的元素
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();
cout << heap.top() << endl;
heap.pop();
heap.output();
heap.heap_sort();
heap.output();
return 0;
}