test24.c

数据结构学习点滴

/***Link operator***/
#include "myhdr.h"

struct data{
	char name[20];
	struct data *next;
	};

typedef struct data PERSON;
typedef PERSON *LINK;

void name_print(LINK p);
LINK creat_list();
void delete_node(LINK p);
void add_node(LINK p);
int get_len(LINK p);
LINK head=NULL;
void menu();
int query_node(LINK p);
int delete_query_node(LINK p);
int
main()
{
	head=creat_list();
	name_print(head);
	menu();
	return 0;
}

void name_print(LINK p)
{
	LINK q;
	q=p;
	while(q!=NULL)
	{
		printf("%s\n",q->name);
		q=q->next;
	}
}

LINK creat_list()
{
	 LINK head=NULL;
	 LINK new =NULL;
	 LINK current=NULL;
	 LINK precurr=NULL; 

 	while(strcmp(new->name,"exit")!=0)
 	{
 		new=(LINK)malloc(sizeof(PERSON));
	
		 if(NULL==new)
         	 {	
		  	printf("%s\n","Memmory allocted error");
 		  	exit(-1);
                 }
                 if(head==NULL)
                 {
                        new->next=NULL;
                        head=new;
                        current=head;
                 }
                 else
                 {
			precurr=current;
                        current->next=new;
                        current=new;
                        current->next=NULL;
                        new->next=NULL;
                 }

                 printf("%s\n","input the name please");
                 scanf("%s",new->name);
                 strcpy(current->name,new->name);
        }
	/***若只有节点"exit",释放为空链***/
	if(head->next==NULL)
	{
		head=NULL;
		free(current);
	}
	/***释放节点"exit"****/
	else
	{
		precurr->next=NULL;
		free(current);
	}
	return head;
}

void delete_node(LINK p)
{
	int count;
	int length;
	int i;
	LINK q;
	LINK de_node;
	q=p;
	/****若链为空，退出****/
	if(p==NULL)
		exit(0);	
	printf("%s\n","input the delete postion of the node");
	scanf("%d",&count);
	length=get_len(head);
	/***删除位置不合法****/
	if(count<1||count>length)
	{
		printf("%s\n","the postion is invalid");
		exit(-1);
	}
	/***删除链首元素***/
	if(count==1)
	{
		head=q->next;
		free(q);
	}
	else
	{
		for(i=1;i<count-1;i++)
		{
			q=q->next;
		}
		/***删除链尾元素***/
		if(count==length)
		{
			free(q->next);
			q->next=NULL;
		}
		/****删除其它元素****/
		else
		{
			de_node=q->next;
		        q->next=de_node->next;
		        free(de_node);
		}
	}
}

void add_node(LINK p)
{
	int count;
        int length;
        int i;
        LINK q;
        LINK add_node;
        q=p;
	printf("%s\n","input the add postion of the node");
        scanf("%d",&count);
	length=get_len(head);
	/***增加节点位置不合法，退出****/
	if(count<=0||count>length+1)
	{
		printf("%s\n","the postion is invalid");
		exit(-1);
	}
	/**为所增加节点分配空间***/
	add_node=(LINK)malloc(sizeof(PERSON));
	if(NULL==add_node)
	{
		printf("%s\n","Memmory allocted error");
		exit(-1);
	}
	printf("%s\n","input the name please");
	scanf("%s",add_node->name);
	/**若增加节点位置在链首***/
	if(count==1)
	{
		/***若为空链***/
		if(p==NULL)
		{
			head=add_node;
			head->next=NULL;
		}
		else
		{
			add_node->next=head;
			head=add_node;
		}
	}
	else
	{
		for(i=1;i<count-1;i++)
		{
			q=q->next;
		}
		/*增加节点位置在链中***/
		if(count<length+1)
		{
			add_node->next=q->next;
			q->next=add_node;
		}
		/**若增加节点位置在链尾***/
		else
		{
			add_node->next=NULL;
			q->next=add_node;
		}
	}		
			
}

int query_node(LINK p)
{
	int count;
	int i=0;
	int j=0;
	LINK q;
	char name[20];
	q=p;
	printf("%s\n","input the query node please");
	scanf("%s",name);	
	fflush(stdin);
	while(q!=NULL)
	{
		count=strcmp(name,q->name);
		i++;
		if(count==0)
		{

			printf("the node exsist,the postion is: %d\n",i);
			j++;
			return i;
		}
		q=q->next;
	}
	if(j==0)
	{
		printf("%s\n","the node is not exsist");
		return -1;
	}
}		

int delete_query_node(LINK p)
{
	int count=0;
	count=query_node(p);
	if(count>0)
	{
		printf("input the count: %d\n",count);
		delete_node(head);
		return 0;
	}
	else
	{
		return -1;
	}
}
int get_len(LINK p)
{
	LINK q;
	int count=1;
	q=p;
	while(q->next!=NULL)
	{
		q=q->next;
		count++;
	}
	return count;
}

void menu()
{
	int count;
	while(1)
	{
		puts("input you choice");
		puts("0 to query");
		puts("1 to delete");
		puts("2 to  add");
		puts("3 to delete_query");
		puts("4 to exit");
		scanf("%d",&count);
		fflush(stdin);
		if(count==0)
		{
			 query_node(head);
		}
		else
		if(count==1)
		{
			delete_node(head);
			printf("%s\n","The deleted list is:");
			name_print(head);
		}
		else
		if(count==2)
		{
			add_node(head);
			printf("%s\n","The added list is:");
			name_print(head);
		}
		else
		if(count==3)
		{
			int return_value;
			return_value=delete_query_node(head);
			if(return_value==0)
			{

		   		printf("%s\n","The deleted list is:");
				name_print(head);
			}
			else
			{
			}
		}
		else
		if(count==4)
		{
			break;
		}
	}
}