Question

I’m attempting to use a linked list implementation to modify another linked list.
Here’s a example of what I’m trying to do.

list<int>list1;
list<int>list2;

list1.push_back( 1 );   // < --- want to modify this list
list1.push_back( 2 );

list2.push_back( 1 );   // with this list

In short, I want to use list2 as kind of like a variable to modify list1. I’ve done some research seems like I can’t access the nodes of the list like an array. Is there a container that allows me to easily add and remove nodes to it and compare and modify it with other containers? I was thinking sets may be an alternative, but it seems as though I can’t access the values in the set either. Any help or evidence would be great. Thanks in advance.

EDIT:::

I’m looking to create a sudoku solver. I put all 81 digits ( blank and given ) into “linked list”. I am now looking to remove possible candidates from each “list” that represents 1 cell.

For example
listlist1;
listlist2;

list1.push_back( 1 );  
list1.push_back( 2 );

list2.push_back( 1 );   

I now want to use list2 like this

list1.remove( list2(?) );  // < -- this obviously isn't possible due to how nodes are stored.

I hope that clears up my question a bit. This is the way I’m using to solve simple sudokus and I’ll implement a brute force technique later.

Answer 1

Here’s is one way, no doubt there’s others. It does depend on exact what you circumstance is. For instance if your lists are sorted there are better way than this.

list<int> list1 = ...;
list<int> list2 = ...;
for (list<int>::const_iterator i = list2.begin(); i != list2.end(); ++i)
  list1.remove(*i);