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copied!<p>Now I can see all the code the problem is very simple. Your deletebeg function is deleting the beginning node with <code>delete</code>, but you didn't allocate the node with <code>new</code>. You should only <code>delete</code> memory if you created it using <code>new</code>.</p> <p>Normally when people write linked list classes they allocate the nodes inside the list methods using <code>new</code>. Then they can safely <code>delete</code> the nodes inside the methods. You are doing the deletes but you are not using new. So you need to rewrite your main function like this</p> <pre><code>int main() { doublelist list1; list1.insertbeg(8); // add 8 to beginning of list list1.insertbeg(7); // add 7 to beginning of list list1.insertafter(4,1); // add 4 after first item of list list1.insertend(9); // add 9 to end of list list1.deletebeg(); } </code></pre> <p>Then you need to rewrite your methods like this</p> <pre><code>void insertbeg(int value)//insert beginning { nodeb* a = new nodeb(value); // allocate node inside of method using new if(head1==0) { head1=a; head2=a; a->next=0; a->pre=0; } else { nodeb *ptr=head1; ptr->pre=a; a->pre=0; a->next=ptr; head1=a; } } </code></pre> <p>I've only shown insertbeg, you need to change all your insert methods in the same way. </p> <p>I'm not promising that's the only problem, but make this change and you'll be on the right way. If you have more problems then post again, but remember <strong>post complete code</strong>. It's the only way you'll get help with problems like this.</p>

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