帮我看一段C语言程序

#include <stdio.h>
#include <malloc.h>

int ture;
struct point
{
int data;
point *next, *last;
} *head = NULL, *tail = NULL;

void QuickSort(struct point *head, struct point *tail)
{
bool op = true;
int t;
struct point *p = head, *q = tail, *tt;
while (p != q)
{
if (op)
{
if (p->data <= q->data)
q = q->last;
else
{
op = false;
t = p->data;
p->data = q->data;
q->data = t;
tt = p;
p = q;
q = tt;
}
}
else
{
if (q->data <= p->data)
q = q->next;
else
{
op = true;
t = p->data;
p->data = q->data;
q->data = t;
tt = p;
p = q;
q = tt;
}
}
}
if (head != p)
QuickSort(head, p->last);
if (tail != p)
QuickSort(p->next, tail);
}