Reversing a singly linked list

[saki]

How do we reverse a singly linked list without using extra
memory.Extra pointers can however be used

 

[Gene]

How do we reverse a singly linked list without using extra
memory.Extra pointers can however be used

In pseudo code, to reverse L, pop elements from L and push onto
(initially empty) R until L is empty. Then return R.

Now in C (untested):

NODE *rev (NODE *lst)
{
NODE *t, *rtn;

rtn = NULL;
while (lst) {

// pop
t = lst;
lst = lst->next;

// push
t->next = rtn;
rtn = t;
}
return rtn;
}

 

[aarklon]

How do we reverse a singly linked list without using extra
memory.Extra pointers can however be used

sn* reverse(sn* p)
{

sn*prev = NULL,*curr =p;
while(curr)
{
p = p -> link;
curr -> link = prev;
prev = curr;
curr = p;
}

return prev;
}