双向链表（作业）

双向列表的结构表示方式

typedef struct DoubleLinkedNode{
      char data;
      struct DoubleLinkedNode *previous;
      struct DoubleLinkedNode *next;
  } DLNode, *DLNodePtr;

 

链表初始化

DLNodePtr initLinkList(){
   	DLNodePtr tempHeader = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
   	tempHeader->data = '\0';
   	tempHeader->previous = NULL;
   	tempHeader->next = NULL;
   	return tempHeader;
   }//Of initLinkList

依次输出

void printList(DLNodePtr paraHeader){
   	DLNodePtr p = paraHeader->next;
   	while(p!=NULL){
   		printf("%c",p->data);
   		p = p->next;
	   }//Of printList
	   printf("\r\n");
}// Of printList

void insertElement(DLNodePtr paraHeader, char paraChar, int paraPosition){
	DLNodePtr p, q, r;

	// Step 1. Search to the position.
	p = paraHeader;
	for (int i = 0; i < paraPosition; i ++) {
		p = p->next;
		if (p == NULL) {
			printf("The position %d is beyond the scope of the list.", paraPosition);
			return;
		}// Of if
	} // Of for i

	// Step 2. Construct a new node.
	q = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
	q->data = paraChar;

	// Step 3. Now link.
	r = p->next;
	q->next = p->next;
	q->previous = p;
	p->next = q;
	if (r != NULL) {
		r->previous = q;
	}// Of if
}// Of insertElement
 

查找

void insertElement(DLNodePtr paraHeader, char paraChar, int paraPosition){
	DLNodePtr p, q, r;

	// Step 1. Search to the position.
	p = paraHeader;
	for (int i = 0; i < paraPosition; i ++) {
		p = p->next;
		if (p == NULL) {
			printf("The position %d is beyond the scope of the list.", paraPosition);
			return;
		}// Of if
	} // Of for i

	// Step 2. Construct a new node.
	q = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
	q->data = paraChar;

	// Step 3. Now link.
	r = p->next;
	q->next = p->next;
	q->previous = p;
	p->next = q;
	if (r != NULL) {
		r->previous = q;
	}// Of if
}// Of insertElement

老师的代码

#include <stdio.h>
#include <malloc.h>

/**
 * Double linked list of integers. The key is char.
 */
  typedef struct DoubleLinkedNode{
      char data;
      struct DoubleLinkedNode *previous;
      struct DoubleLinkedNode *next;
  } DLNode, *DLNodePtr;
  
  /**
   * Initialize the list with a header.
   * @return The pointer to the header.
   */
   DLNodePtr initLinkList(){
   	DLNodePtr tempHeader = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
   	tempHeader->data = '\0';
   	tempHeader->previous = NULL;
   	tempHeader->next = NULL;
   	return tempHeader;
   }//Of initLinkList
   
   /**
    *Print the list.
    *@para paraHeader The header of the list.
    */
   void printList(DLNodePtr paraHeader){
   	DLNodePtr p = paraHeader->next;
   	while(p!=NULL){
   		printf("%c",p->data);
   		p = p->next;
	   }//Of printList
	   printf("\r\n");
}// Of printList

/**
 *Insert an element to the given position.
 * @param paraHeader The header of the list.
 * @param paraChar The given char.
 * @param paraPosition The given poaition.
 */
 void insertElement(DLNodePtr paraHeader, char paraChar, int paraPosition){
	DLNodePtr p, q, r;

	// Step 1. Search to the position.
	p = paraHeader;
	for (int i = 0; i < paraPosition; i ++) {
		p = p->next;
		if (p == NULL) {
			printf("The position %d is beyond the scope of the list.", paraPosition);
			return;
		}// Of if
	} // Of for i

	// Step 2. Construct a new node.
	q = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
	q->data = paraChar;

	// Step 3. Now link.
	r = p->next;
	q->next = p->next;
	q->previous = p;
	p->next = q;
	if (r != NULL) {
		r->previous = q;
	}// Of if
}// Of insertElement
 
 /**
  *Delete an element from the liat.
  *@param paraHeader The header of the list.
  *@param paraChar The given char.
  */
   void deleteElement(DLNodePtr paraHeader, char paraChar){
   	DLNodePtr p,q,r;
   	p = paraHeader;
   	
   	// step 1. Locata.
   	while ((p->next != NULL) && (p->next->data != paraChar)){
   		p =p->next;
	   }// of while
	   
	   //step 2. Error check
	   if(p->next == NULL){
	   	printf("The char '%c' does not exist.\r\n",paraChar);
	   	return;
	   }//of if
	   
	   // step 3. Change links.
	   q = p->next;
	   r = q->next;
	   p->next = r;
	   if(r!=NULL){
	   r->previous = p;   
   }// of if
   
   // step 4.free the space
   free(q);
} // of deleteElement

/**
 * Unit test
 */
 void insertDeleteTest(){
 	// step 1.Inittialize an empty list.
 	DLNodePtr tempList = initLinkList();
 	printList(tempList);
 	
 	// step2. Add some characters.
 	insertElement(tempList,'H',0);
 	insertElement(tempList,'e',1);
 	insertElement(tempList,'l',2);
 	insertElement(tempList,'l',3);
 	insertElement(tempList,'o',4);
 	insertElement(tempList,'!',5);
 	printList(tempList);
 	
 	// step 3. Delete some charcters (the first occurrence).
 	deleteElement(tempList,'e');
 	deleteElement(tempList,'a');
 	deleteElement(tempList,'o');
 	printList(tempList);
 	
 	//step 4. Insert to a given position.
 	insertElement(tempList, 'o',1);
 	printList(tempList);
 }// of appendInsertDeleteTest

/**
 *Address test: beyond the book.
 */
 void basicAddressTest(){
 	DLNode tempNode1, tempNode2;
 	
 	tempNode1.data = 4;
 	tempNode1.next = NULL;
 	
 	tempNode1.data = 6;
 	tempNode1.next = NULL;
 	
 	printf("The first node:%d,%d,%d\r\n",
	    &tempNode1, &tempNode1.data, &tempNode1.next);
	    printf("The second node:%d,%d,%d\r\n",
	    &tempNode2, &tempNode2.data, &tempNode2.next);
	    
	tempNode1.next = &tempNode2;
 }// of basicAddressTest
 
 /**
  * The entrance.
  */
 int main(){
 	insertDeleteTest();
 	basicAddressTest();
 }// of main
 	
 	

运行结构

 新增代码

char getElement(DLNodePtr paraHeader,int i)
{
	DLNode p;
	int j=1;
	p=paraHeader->next;
	while(p&&j<i)
	{
		p=p->next;
		j++;
	}
	if(!p || j>i)
	{
		printf("ERROR number");
		return -1;
	}
	return p->data;
}

链表长度

int Lengthlist(DLNodePtr paraHeader,int i)
{
	DLNodePtr p;
	int i=0;
	p=paraHeader->next;
	while(p)
	{
		i++;
		p=p->next;
	}
	return i;
}

查找

int locateElement(DLNodePtr paraHeader, char paraChar)
{
    int i=0;
    DLNodePtr p=paraHeader->next;
    while(p)
    {
        i++;
        if(p->data==paraChar)
        return i;
        p=p->next;
    }
    return 0;
}

完整代码

#include <stdio.h>
#include <malloc.h>

/**
 * Double linked list of integers. The key is char.
 */
  typedef struct DoubleLinkedNode{
      char data;
      struct DoubleLinkedNode *previous;
      struct DoubleLinkedNode *next;
  } DLNode, *DLNodePtr;
  
  /**
   * Initialize the list with a header.
   * @return The pointer to the header.
   */
   DLNodePtr initLinkList(){
   	DLNodePtr tempHeader = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
   	tempHeader->data = '\0';
   	tempHeader->previous = NULL;
   	tempHeader->next = NULL;
   	return tempHeader;
   }//Of initLinkList
   
   /**
    *Print the list.
    *@para paraHeader The header of the list.
    */
   void printList(DLNodePtr paraHeader){
   	DLNodePtr p = paraHeader->next;
   	while(p!=NULL){
   		printf("%c",p->data);
   		p = p->next;
	   }//Of printList
	   printf("\r\n");
}// Of printList

/**
 *Insert an element to the given position.
 * @param paraHeader The header of the list.
 * @param paraChar The given char.
 * @param paraPosition The given poaition.
 */
 void insertElement(DLNodePtr paraHeader, char paraChar, int paraPosition){
	DLNodePtr p, q, r;

	// Step 1. Search to the position.
	p = paraHeader;
	for (int i = 0; i < paraPosition; i ++) {
		p = p->next;
		if (p == NULL) {
			printf("The position %d is beyond the scope of the list.", paraPosition);
			return;
		}// Of if
	} // Of for i

	// Step 2. Construct a new node.
	q = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
	q->data = paraChar;

	// Step 3. Now link.
	r = p->next;
	q->next = p->next;
	q->previous = p;
	p->next = q;
	if (r != NULL) {
		r->previous = q;
	}// Of if
}// Of insertElement
 
 /**
  *Delete an element from the liat.
  *@param paraHeader The header of the list.
  *@param paraChar The given char.
  */
   void deleteElement(DLNodePtr paraHeader, char paraChar){
   	DLNodePtr p,q,r;
   	p = paraHeader;
   	
   	// step 1. Locata.
   	while ((p->next != NULL) && (p->next->data != paraChar)){
   		p =p->next;
	   }// of while
	   
	   //step 2. Error check
	   if(p->next == NULL){
	   	printf("The char '%c' does not exist.\r\n",paraChar);
	   	return;
	   }//of if
	   
	   // step 3. Change links.
	   q = p->next;
	   r = q->next;
	   p->next = r;
	   if(r!=NULL){
	   r->previous = p;   
   }// of if
   
   // step 4.free the space
   free(q);
} // of deleteElement

/**
 * Unit test
 */
 char getElement(DLNodePtr paraHeader,int i)
{
	DLNodePtr p;
	int j=1;
	p=paraHeader->next;
	while(p&&j<i)
	{
		p=p->next;
		j++;
	}
	if(!p || j>i)
	{
		printf("ERROR number");
		return -1;
	}
	return p->data;
}

int locateElement(DLNodePtr paraHeader, char paraChar)
{
    int i=0;
    DLNodePtr p=paraHeader->next;
    while(p)
    {
        i++;
        if(p->data==paraChar)
        return i;
        p=p->next;
    }
    return 0;
}


 int listLength(DLNodePtr paraHeader,int i)
{
	DLNodePtr p;
     i=0;
	p=paraHeader->next;
	while(p)
	{
		i++;
		p=p->next;
	}
	return i;
}
 void insertDeleteTest(){
 	// step 1.Inittialize an empty list.
 	DLNodePtr tempList = initLinkList();
 	printList(tempList);
 	
 	// step2. Add some characters.
 	insertElement(tempList,'A',0);
 	insertElement(tempList,'p',1);
 	insertElement(tempList,'p',2);
 	insertElement(tempList,'l',3);
 	insertElement(tempList,'e',4);
 	insertElement(tempList,'o',5);
 	printList(tempList);
 	getElement(tempList,1);
 	locateElement(tempList,'o');
 	
 	printf("The first element is %c\n",getElement(tempList,1));
 	printf("'o' is at the %d position in the list\n",locateElement(tempList,'o'));
 	
 	// step 3. Delete some charcters (the first occurrence).
 	deleteElement(tempList,'p');
 	deleteElement(tempList,'l');
 	deleteElement(tempList,'e');
 	printList(tempList);
 	
 	//step 4. Insert to a given position.
 	insertElement(tempList, 'A',1);
 	printList(tempList);
 }// of appendInsertDeleteTest

/**
 *Address test: beyond the book.
 */
 void basicAddressTest(){
 	DLNode tempNode1, tempNode2;
 	
 	tempNode1.data = 4;
 	tempNode1.next = NULL;
 	
 	tempNode1.data = 6;
 	tempNode1.next = NULL;
 	
 	printf("The first node:%d,%d,%d\r\n",
	    &tempNode1, &tempNode1.data, &tempNode1.next);
	    printf("The second node:%d,%d,%d\r\n",
	    &tempNode2, &tempNode2.data, &tempNode2.next);
	    
	tempNode1.next = &tempNode2;
 }// of basicAddressTest
 
 /**
  * The entrance.
  */
 int main(){
 	insertDeleteTest();
 	basicAddressTest();
 }// of main
 	
 	

运行结果