划分链表

小于于divot的放前边,等于divot的放中间，大于divot的放后边

//划分链表，小于pivot的放前面，等于pivot的放中间,大于pivot的放后边
TreeList* partition_list(TreeList*p, int pivot) {
	TreeList* sH = NULL;
	TreeList*sT = NULL;
	TreeList *eH = NULL;
	TreeList* eT = NULL;
	TreeList *bH = NULL;
	TreeList*bT = NULL;
	TreeList* next = NULL;
	while (p) {
		next = p->next;
		p->next = NULL;
		if (p->val < pivot) {
			if (sH ==NULL) {
				sH = p;
				sT = p;
			}
			else {
				sT->next = p;
				sT = p;
			}
		}
		else if (p->val == pivot) {
			if (eH == NULL) {
				eH = p;
				eT = p;
			}
			else {
				eT->next = p;
				eT = p;
			}

		}
		else {
			if (bH == NULL) {
				bH = p;
				bT = p;
			}
			else {
				bT->next = p;
				bT = p;
			}
		}
		p = next;
	}
	if (sH != NULL) {
		p = sH;
		sT->next = eH;
	}
	else if (eH != NULL) {
		p = eH;
		eT->next = bH;
	}
	else {
		p = bH;
	}
	return p;
}