【面试题】剑指offer 13

在O（1）时间删除链表节点

listnode.h

#include
#include
using namespace std;
struct ListNode
{
	int _value;
	ListNode* pNext;
};
class List
{
public:
	List()
		:pHead(NULL)
	{}
	~List()
	{
		delete pHead;
		pHead=NULL;
	}
	void deleteNode(ListNode* todelete)
	{
		assert(todelete);
		if (todelete->pNext!=NULL)
		{
			ListNode* next=todelete->pNext;
			todelete->_value=next->_value;
			todelete->pNext=next->pNext;
			delete next;
			next=NULL;
		}
		else if(pHead==todelete)
		{
			delete todelete;
			todelete=NULL;
			pHead=NULL;
		}
		else
		{
			ListNode* node=pHead;
			while (node->pNext!=todelete)
			{
				node=node->pNext;
			}
			node->pNext=NULL;
			delete todelete;
			todelete=NULL;
		}
	}
	void addNode(const int value)
	{
			ListNode* newnode=new ListNode();
	        if (pHead==NULL)
	        {
				newnode->_value=value;
				newnode->pNext=NULL;
				pHead=newnode;
				return;
	        }
			ListNode* node=pHead;
			while(node->pNext!=NULL)
			{
				node=node->pNext;
			}
			newnode->_value=value;
			newnode->pNext=NULL;
			node->pNext=newnode;
		
	}
	void printNodeValue()
	{
		ListNode* node=pHead;
		while (node)
		{
			cout<_value<<" ";
			node=node->pNext;
		}
		cout<_value==x)
		break;
		node=node->pNext;
	}
	return node;
}
ListNode* getHead()
{
	return pHead;
}
private:
	ListNode* pHead;
};
void test()
{
	List l;
	l.addNode(1);
	l.addNode(2);
	l.addNode(3);
	l.addNode(4);
	l.addNode(5);
	l.addNode(6);
	l.addNode(7);
	l.addNode(8);
	l.addNode(9);
	l.printNodeValue();
	l.deleteNode(l.Find(5));
	l.printNodeValue();

}

test.c

#include "ListNode.h"
int main()
{
	test();
	system("pause");
	return 0;
}