qsort.c

unix环境下实现的cmm语言编译器

void swap(char *v[], int i, int j);
/*qsort:按递增顺序对v[left]...v[right]进行排序*/
void qsort(char *v[], int left, int right,
			 int (*comp)(void *, void *))
{
	int i, last;
	
	if (left >= right)
		return ;
	swap(v, left, (left + right)/2);
	last = left;
	i = left + 1;
	while (i <= right) {
		if ((*comp)(v[i], v[left]) < 0) {
			last = last + 1;
			swap(v, last, i);
		}
		i = i + 1;
	}
	swap(v, left, last);
	qsort(v, left, last-1,comp);
	qsort(v, last+1, right,comp);
}

/*swap:交换v[i]和v[j]*/
void swap(char *v[], int i, int j)
{
	char *temp;
	temp = v[i];
	v[i] = v[j];
	v[j] = temp;
}