数据结构C++（单链表）

#include
using namespace std;

class ListNode
{
	public :
	ListNode * next;
	int val;
	
	ListNode(int _val = 0)
	{
		next = NULL;
		val = _val;
	}
};

class List
{
	
	int length;
	ListNode * p;
	ListNode * q;
	
	public:
		ListNode* head;
		
		List()
		{
			head = NULL;
			length = 0;
		}
		
		void push_back(int val)
		{
			if(head == NULL)
			{
				head = new ListNode(val);
				length++;
				return ;
			}
			ListNode * newNode = new ListNode(val);
			p = head;
			while(p!=NULL&&p->next!=NULL)
			{
				p=p->next;
			}
			p->next = newNode;
			length++;
		}
		
		ListNode * RemoveAt(int index)
		{
			if(index<0||index>=length)
			{
				return NULL;
			}
			if(index==0)
			{
				p=head;
				head = p->next;
				length--;
				return p;
			}
			p=head;
			for(int i=0;i
				p=p->next;
			}
			q = p->next;
			p->next=q->next;
			length--;
			return q;
		}
		
		void show()
		{
			p = head;
			while(p!=NULL)
			{
				cout<val<next;
			}
		}
};

int main()
{
	List a;
	a.push_back(1);
	a.push_back(2);
	a.push_back(3);
	a.push_back(4);
	a.show();
}