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POC++ vector of pointers problem
 

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    <p>I'm currently trying to implement the A* pathfinding algorithm using C++.</p> <p>I'm having some problems with pointers... I usually find a way to avoid using them but now I guess I have to use them.</p> <p>So let's say I have a "node" class(not related to A*) implemented like this:</p> <pre><code>class Node { public: int x; Node *parent; Node(int _x, Node *_parent) : x(_x), parent(_parent) { } bool operator==(const Node &amp;rhs) { return x == rhs.x &amp;&amp; parent == rhs.parent; } }; </code></pre> <p>It has a value (in this case, int x) and a parent (a pointer to another node) used to navigate through nodes with the parent pointers.</p> <p>Now, I want to have a list of nodes which contains all the nodes that have been or are being considered. It would look like this:</p> <pre><code>std::vector&lt;Node&gt; nodes; </code></pre> <p>I want a list that contains pointers pointing to nodes inside the <em>nodes</em> list. Declared like this:</p> <pre><code>std::vector&lt;Node*&gt; list; </code></pre> <p>However, I'm definitely not understanding pointers properly because my code won't work. Here's the code I'm talking about:</p> <pre><code>std::vector&lt;Node&gt; nodes;//nodes that have been considered std::vector&lt;Node*&gt; list;//pointers to nodes insided the nodes list. Node node1(1, NULL);//create a node with a x value of 1 and no parent Node node2(2, &amp;node1);//create a node with a x value of 2 and node1 being its parent nodes.push_back(node1); list.push_back(&amp;nodes[0]); //so far it works //as soon as I add node2 to nodes, the pointer in "list" points to an object with //strange data, with a x value of -17891602 and a parent 0xfeeefeee nodes.push_back(node2); list.push_back(&amp;nodes[1]); </code></pre> <p>There is clearly undefined behaviour going on, but I can't manage to see where. Could somebody please show me where my lack of understanding of pointers breaks this code and why?</p>
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