Linked list and function

[stj]

Hi all

i can't understand the output of this code

node* test(node* &X) {
	node *t=X;
	t=t->next;
	node*k=X->next->next->next;
	X=k->next;
	k->next=0;
	return t;
}

Assuming X is a linked list and its struct is defined:

struct node{int info; node* next; nodo(int a=0, nodo* b=0){info=a; next=b;}};

And X has following nodes value:

1->2->3->4->5->6->7->8->9

And of course if i print X after text the remaining list is:

4->5->6->7->8->9

Because of X=k->next;

The thing that i don't undesrtand is why after k->next=0; X doesn't change but if i print t the output is
2->3->4
Look like k->next=0 modify even t but not X, could someone please explain me?

Thanks

[keskiverto]

Does this help?

1 2 3 4 5 6 7 8 9

node* test( node* & X ) { node* t = X; t = t->next; node* k = X->next->next->next; X = k->next; k->next = 0; return t; }

1->2->3->4->5->6->7->8->9 X t t k X 1->2->3->4 5->6->7->8->9

PS 1. If X was the only pointer to 1, then after the function nothing points to 1 any more: a memory leak.

PS 2. If list does not have enough elements, then the function has undefined results.