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  • 3 Post By Adak
  • 1 Post By CommonTater

Copying a linked list into another linked list

This is a discussion on Copying a linked list into another linked list within the C Programming forums, part of the General Programming Boards category; Hi, I want to write a copy_list function that creates a linked list(the function result) with new nodes that contain ...

  1. #1
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    Copying a linked list into another linked list

    Hi,
    I want to write a copy_list function that creates a linked list(the function result) with new nodes that contain the same data as the linked list referenced by the single argument of copy_list
    My structures:
    Code:
    typedef struct name_node_s {
      char name[11];
      struct name_node_s *restp;
    }name_node_t;
    typedef struct {
      name_node_t *headp;
      int size;
    }name_list_t;
    Copy_list function:
    Code:
    name_node_t *copy_list(name_node_t *head){
    	name_node_t *current = head;
    	name_node_t *newList = NULL;
    	name_node_t *tail = NULL;
    	
    	while (current != NULL){
    		if (newList == NULL) {
    			newList = malloc(sizeof(name_node_t));
    			strcpy(newList->name, current->name);
    			newList->restp = NULL;
    			tail = newList;
    		}
    		else {
    			tail->restp = malloc(sizeof(name_node_t));
    			tail = tail->restp;
    			strcpy(tail->name, current->name);
    			tail->restp = NULL;
    		}
    		current = current->restp;
    	}
    	return(newList);
    }
    And rest of code:
    Code:
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    
    typedef struct name_node_s {
      char name[11];
      struct name_node_s *restp;
    }name_node_t;
    typedef struct {
      name_node_t *headp;
      int size;
    }name_list_t;
    name_node_t* presidents(void);
    void insertAfter(name_node_t* mynode,name_node_t* newNode);
    //void delete_last(name_node_t** headRef);
    //void ListDelete(name_list_t* listP, char pname[]);
    void lastDelete(name_list_t* listP);
    void place_first(name_node_t **headRef, char pname[]);
    name_node_t *copy_list(name_node_t *head);
    int main(void)
    {
      name_list_t list;
      name_list_t list_two;
      //name_node_t *np, *qp;
      list.headp = presidents();
      name_node_t *new_node;
      new_node = malloc(sizeof(name_node_t));
      strcpy(new_node->name, "Eisenhower");
      insertAfter(list.headp->restp, new_node);
      lastDelete(&list);
      place_first(&list.headp, "Mustafa");
      printf("%s %s %s %s", list.headp->name, list.headp->restp->name, list.headp->restp->restp->name, list.headp->restp->restp->restp->name);
      list_two.headp = copy_list(list.headp);
      printf("%s %s %s %s", list_two.headp->name, list.headp->restp->name, list.headp->restp->restp->name, list.headp->restp->restp->restp->name);
    
      return(0);
    }
    name_node_t* presidents(void)
    {
      name_node_t* head = NULL;
      name_node_t* second = NULL;
      name_node_t* third = NULL;
      
      head = malloc(sizeof(name_node_t));
      second = malloc(sizeof(name_node_t));
      third = malloc (sizeof(name_node_t));
    
      strcpy(head->name, "Washington");
      head->restp = second;
        
      strcpy(second->name, "Roosevelt");
      second->restp = third;
    
      strcpy(third->name, "Kennedy");
      third->restp = NULL;
    
      return(head);
    }
    void insertAfter(name_node_t* mynode,name_node_t* newNode)
    {
    	newNode->restp = mynode->restp;
    	mynode->restp = newNode;
    }
    
    void ListDelete(name_list_t* listP, char pname[]){
    	name_node_t *to_freep, *cur_nodep;
    	if(strcmp(listP->headp->name, pname)){
    		to_freep = listP->headp;
    		listP->headp = to_freep->restp;
    		--(listP->size);
    	}
    	else {
    		for (cur_nodep = listP->headp;
    			cur_nodep->restp != NULL && !strcmp(cur_nodep->restp->name, pname);
    			cur_nodep = cur_nodep->restp) {
    				if( cur_nodep->restp != NULL && strcmp(cur_nodep->restp->name, pname)) {
    					to_freep = cur_nodep->restp;
    					cur_nodep->restp = to_freep->restp;
    					free(to_freep);
    					--(listP->size);
    				}
    			}
    		}
    	}
    void lastDelete(name_list_t* listP){
    	name_node_t *to_freep, *cur_nodep;
    	for (cur_nodep = listP->headp;
    			cur_nodep->restp != NULL;
    			cur_nodep = cur_nodep->restp) {}
    	to_freep = cur_nodep;
    	cur_nodep->restp = to_freep->restp;
    	free(to_freep);
    	--(listP->size);
    }
    void place_first(name_node_t **headRef, char pname[]) {
    	name_node_t *newNode = malloc(sizeof(name_node_t));
    	strcpy(newNode->name, pname);
    	newNode->restp = *headRef;
    	*headRef = newNode;
    }
    /*name_node_t *copy_list(name_node_t *head) {
    	name_node_t *current = head;
    	name_node_t *newList = NULL;
    	name_node_t **lastPtr;
    	
    	lastPtr = &newList;
    	
    	while (current != NULL) {
    		printf("**");
    		place_first(lastPtr, current->name);
    		lastPtr = &((*lastPtr)->restp);
    		current = current->restp;
    	}
    	return(newList);
    }*/
    /*name_node_t *copy_list(name_node_t *head) {
    	if (head == NULL)
    		return NULL;
    	else {
    		name_node_t *newList = malloc(sizeof(name_list_t));
    		strcpy(newList->name, head->name);
    		newList->restp = copy_list(head->restp);
    		
    		return(newList);
    	}
    }*/
    name_node_t *copy_list(name_node_t *head){
    	name_node_t *current = head;
    	name_node_t *newList = NULL;
    	name_node_t *tail = NULL;
    	
    	while (current != NULL){
    		if (newList == NULL) {
    			newList = malloc(sizeof(name_node_t));
    			strcpy(newList->name, current->name);
    			newList->restp = NULL;
    			tail = newList;
    		}
    		else {
    			tail->restp = malloc(sizeof(name_node_t));
    			tail = tail->restp;
    			strcpy(tail->name, current->name);
    			tail->restp = NULL;
    		}
    		current = current->restp;
    	}
    	return(newList);
    }

  2. #2
    Registered User whiteflags's Avatar
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    What did you want to actually ask?

  3. #3
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    My function(copy_list) doesn't work.I can't figure out where is the problem.

  4. #4
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    What is the exact problem, how does it not work?
    Quote Originally Posted by anduril462 View Post
    Now, please, for the love of all things good and holy, think about what you're doing! Don't just run around willy-nilly, coding like a drunk two-year-old....
    Quote Originally Posted by quzah View Post
    ..... Just don't be surprised when I say you aren't using standard C anymore, and as such,are off in your own little universe that I will completely disregard.
    Warning: Some or all of my posted code may be non-standard and as such should not be used and in no case looked at.

  5. #5
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    Oh sure! Now Andrew wants the problem to actually be described for him!

    So spoiled! < LOL >

  6. #6
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    Quote Originally Posted by Adak View Post
    Oh sure! Now Andrew wants the problem to actually be described for him!

    So spoiled! < LOL >
    LOL..... I know I am such a prima donna!
    Quote Originally Posted by anduril462 View Post
    Now, please, for the love of all things good and holy, think about what you're doing! Don't just run around willy-nilly, coding like a drunk two-year-old....
    Quote Originally Posted by quzah View Post
    ..... Just don't be surprised when I say you aren't using standard C anymore, and as such,are off in your own little universe that I will completely disregard.
    Warning: Some or all of my posted code may be non-standard and as such should not be used and in no case looked at.

  7. #7
    ATH0 quzah's Avatar
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    Code:
    struct node *ldupe( struct node *o )
    {
        struct node *n = o;
        if( o )
        {
            n = malloc( sizeof *n );
            if( n )
            {
                *n = *o;
                n->next = ldupe( o->next );
            }
        }
        return n;
    }
    Hm... that looks fun.


    Quzah.
    Hope is the first step on the road to disappointment.

  8. #8
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    Quote Originally Posted by AndrewHunter View Post
    LOL..... I know I am such a prima donna!
    Heck man... we already knew that...
    AndrewHunter likes this.

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