how to reverse link list using recurtion
 

please can someone give me code how to reverse single link list using recurtion

thanks

Re: how to reverse link list using recurtion
 

Show an attempt.

Re: how to reverse link list using recurtion
 

Ohhh I am new to the forum and I was not knowing the rules :mrgreen: :p That I have to show attempt ...

Here is what I was trying to do ! :evil: :evil:

Without Recurtion :-)

struct node *p,*q,*r;

r=null;

p=head;

while(p)

{

    q=p->next;

    p->next=r;

    r=p;

    p=q;

}

head=p;

With recurtion :

   list *tail;  

 

list *reverse (list *head)  

{  

  if (head->next == NULL)  

  {  

    tail = head;  

    return;  

  }else{  

    reverse (head->next);  

    head->next->next = head;  

    head->next = NULL;  

  }  

}

<< moderator edit: added [code][/code] tags >>



In general can we reverse link list using REFERERCNCE to pointer as function parameter .... :idea:

Re: how to reverse link list using recurtion
 

You're on the right track. Try incorporating a temporary link into your function rather than trying to work just with head and its next links.

Re: how to reverse link list using recurtion
 

Temperary variable to be passed in recursive function :evil: ??

temparary variable are temparary to scope of function and in recursive function we use global variable sort of things :rolleyes:

In general we can use static pointer but then toomit does not workk


CAN ANYONE HELP ME ITS URGENT :cry: :cry:

Re: how to reverse link list using recurtion
 

>> Temperary variable to be passed in recursive function
No.

>> temparary variable are temparary to scope of function
Yea.

>> and in recursive function we use global variable sort of things
What are you babbling about? It's possible and perfectly reasonable to use a non-static local variable in a recursive function. This function doesn't need a static variable or a global variable. Here's your current function:

list *reverse (list *head)

{

  if (head->next == NULL)

  {

    tail = head;

    return;

  }else{

    reverse (head->next);

    head->next->next = head;

    head->next = NULL;

  }

}

Here's my modification using a local temporary:

link *reverse_list(link *head)

{

  link *temp;



  if (head->next == 0) temp = head;

  else {

    temp = reverse_list(head->next);

    head->next->next = head;

    head->next = 0;

  }



  return temp;

}

The algorithm is identical, but my function is completely self-contained and works properly whereas yours would have unnecessary coupling with that global variable if you kept following the same line of thinking.

Re: how to reverse link list using recurtion
 

Ohhh thanks .....Its finally working ..