单链表

       遇到的问题:主要还是指针问题，还有算法思想要清晰。

在删除时对于相同的数只能删除一次。不知什么原因。在GCC上运行却可以删除相同的数多次。    

代码：

 

#include <iostream>

#include <cstdlib>

using namespace std;

typedef struct ListNode

{

	int data;

	struct ListNode *next;

}*List;



void createList(List &list,int arr[],int n)

{

	 List head,node;

	 list=(List)malloc(sizeof(List));

	 list->next=NULL;

	 head=list;

	 for(int i=0;i<n;i++)

	 {

         node=(List)malloc(sizeof(List));

		 if(!node)

			 cout<<"内存分配失败."<<endl;

		 else

		 {

			 node->data=arr[i];

			 node->next=head->next;

			 head->next=node;

		 }

	 }



}



void insertListNode(List list,int elem)

{

	 List node,head,pre;

	 node=(List)malloc(sizeof(List));

	 node->data=elem;

	 node->next=NULL;

     head=list->next;

	 pre=list;

	 while(head)

	 {

		 if(head->data>elem)

		 {  

			 pre=head;

			 head=head->next;

			 if(head==NULL)

			 {

				 pre->next=node;

				 break;

			 }

		 }

		 else

		 {

			 node->next=pre->next;

			 pre->next=node;

			 break;

		 }

	 }



}



void deleteListNode(List list,int elem)

{

	List head,pre,node;

	head=list->next;

	pre=list;

	while(head)

	{

		if(head->data==elem)

		{

			node=head;

			pre->next=head->next;

	        break;

		}

		else

		{

			pre=head;

			head=head->next;

			if(head->next==NULL)

			{   

				if(head->data==elem)

				pre->next=NULL;

				free(head);

				break;

			}

		}

	}

}

void merge(List list1,List list2)

{

	 List head=list1->next;

	 while(head)

	 {

		head=head->next;

		 if(head->next==NULL)

			break;

	 }

	 head->next=list2->next;

}



void display(List list)

{

	List head;

	head=list->next;

	while(head)

	{

		cout<<head->data<<"->";

		head=head->next;

	}

	cout<<endl;



}



int main()

{

	List list,list2;

	int arr[]={1,5,74,3,5,8};

	int arr2[]={4,38,45,2};

	createList(list,arr,6);

	createList(list2,arr2,4);

	cout<<"display list:";

	display(list);



	insertListNode(list,23);

	cout<<"display list:";

	display(list);

	insertListNode(list,6);

	cout<<"display list:";

	display(list);



	deleteListNode(list,5);

	cout<<"display list:";

	display(list);



	merge(list,list2);

	cout<<"display list:";

	display(list);

	return 0;

}

运行结果: