Hi all,

I wrote a program that has many functionalities but I can not swap 2 elements of 2 nodes in the linked list.Actually I can swap 2 nodes by changing their links but I can not swap 2 elements when the user requested 2 elements swapping.Here is my code without any swap operation.Again I have to say I want to do this swap operation by swapping 2 node elements not changing node links.How can I get rid of this problem?Any help will be appreciated.

#include <stdio.h>
#include <stdlib.h>

struct node{
  int data;
  struct node *next;
     };
typedef struct node nodetype;

void insert(int ,struct node **);
void display(struct node *);
void search(int, struct node *);
void delete(int, struct node **);
int main(void){

    nodetype *p;
    p=NULL;
    int x=0,choice;
    int s_no,k,r_no;


    while(x!=1){
        printf("enter 1 for insert\n");
        printf("enter 2 for display\n");
        printf("enter 3 for search\n");
        printf("enter 4 for delete\n");

        printf("enter 0 for exit\n");
        fflush(stdout);
        scanf("%d",&choice);
        if(choice==1){
            printf("enter inserted  no\n");
            fflush(stdout);
             scanf("%d",&k);
            insert(k,&p);
        }

        else if(choice==2)
            display(p);
        else if(choice==3){
            printf("enter searched no\n");
            scanf("%d",&s_no);
            search(s_no, p);
        }
        else if(choice==4){
            printf("enter deleted no\n");
            scanf("%d",&r_no);
            delete(r_no,&p);
                }
        else
            printf("invalid choice\n");
    }
    return 0;
}
void display ( struct node *p)
{
    printf("the content is:\n");
    if(p==NULL)
        printf("the link is empty\n");
    while ( p != NULL )
    {
        printf ( "%d ", p -> data ) ;
        p = p -> next ;
    }
 printf ( "\n" ) ;
}

void search(int no, struct node *p){
   nodetype * loc;
   for(loc=p;loc!=NULL;loc=loc->next)
    {
     if(no==loc->data){
       printf("\nthe number exist in the list\n");
       return;
     }

    }
   printf("\nthe number is not exist in the \n");
 }
void insert(int x,struct node **p)
{
    struct node *r,*temp=*p;
    r = (struct node *)malloc ( sizeof (struct node)) ;
    r ->data = x ;
    r->next=NULL;
    if ( *p == NULL)
    {
        *p = r ;
    }
    else
    {
        while(temp->next!= NULL)
        {
                  temp=temp->next;
        }

     temp->next=r;
    }
}
void delete(int num, struct node **p){
  struct node *temp,*x;
  temp=*p;
  x= NULL;
  while (temp->next !=NULL){
    if(temp->data == num)
     {
      if (x==NULL)
       {
        *p = temp->next;
        free(temp);
        return;
       }
      else
       {
        x->next = temp->next;
        free(temp);
        return;
       }
     }
    x=temp;
    temp=temp->next;
  }
  printf(" No such entry to delete ");
}

Edited 3 Years Ago by mike_2000_17: Fixed formatting

All you have to do is swap the data item of the two nodes -- just like you would swap any two integers.

And please use code tags the next time you post code so that people can read it.

As Ancient Dragon said
All you have to do is swap the data item of the two nodes -- just like you would swap any two integers.

But be careful while dealing with pointers.

If the data item is a pointer, then again all you have to do is swap pointer values, no need to actually copy the data that the pointers point to. The same goes for other objects as well.

Edited 5 Years Ago by Ancient Dragon: n/a

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