八大排序之堆排序

#pragma once

void AdjustDown(int*a,size_t size, size_t parent)
{
size_t child = parent * 2 + 1;
while (child < size)
{
if (child + 1 < size&&a[child + 1] > a[child])
{
child++;
}
if (a[child]>a[parent])
{
swap(a[child], a[parent]);
parent = child;
child = parent * 2 + 1;
}
else
{
break;
}
}
}
void HeapSort(int *a,size_t size)
{
for (size_t i = (size - 2) / 2; i >= 0; i--)
{
AdjustDown(a,size,i);
}
for (size_t i = 0; i < size; i++)
{
swap(a[0], a[size - 1 - i]);
AdjustDown(a, size - 1 - i, 0);
}
}