Thread: Am I forgetting any cleanup/safety checks that I should be using? (Linked lists)

  1. #1
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    Am I forgetting any cleanup/safety checks that I should be using? (Linked lists)

    I was just wondering if in this code (which works) I am forgetting anything to clean up / protect myself from accessing garbage memory, etc. I wasn't sure in my functions if I should delete or if they're automatically destroyed at the end of the function.

    Thank you for your time, in advance.

    Code:
    #include <iostream>
    #include <ctime>
    
    // Node prototype
    
    struct node
    {
    	int x;
    	node *next;
    };
    
    // Function prototypes
    
    node* NewNode(node *end);
    int TravList(node *root);
    
    // Code
    
    int main()
    {
    	srand(time(NULL));
    	
    	node *root, *link;
    	root = new node;
    	
    	root->next = 0;
    	root->x = 5;
    	
    	link = NewNode(root);
    	link = NewNode(link);
    	
    	TravList(root);
    	
    	std::cin.get();
    	return(0);
    }
    
    node* NewNode(node *root)
    {
    	node *link;
    	link = root;
    	
    	link->next = new node;
    	link = link->next;
    	link->next = 0;
    	link->x = (rand()%100 + 1);
    	
    	root->next = link;
    	
    	return(link);
    }
    
    int TravList(node *root)
    {
    	node *link;
    	link = root;
    	
    	while (link->next != 0)
    	{
    		std::cout << link->x << "\n";
    		link = link->next;
    	}
    	
    	std::cout << link->x;
    	
    	return(0);
    }

  2. #2
    Registered User hk_mp5kpdw's Avatar
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    You should have some kind of DeleteList function that cleans up all that allocated memory, something similar to your TravList function that calls delete on the nodes in the list instead of performing output.
    "Owners of dogs will have noticed that, if you provide them with food and water and shelter and affection, they will think you are god. Whereas owners of cats are compelled to realize that, if you provide them with food and water and shelter and affection, they draw the conclusion that they are gods."
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  3. #3
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    Ok, something like..

    Code:
    int DelList(node *root)
    {
    	node *link, *temp;
    	link = root;
    	
    	while (link->next != 0)
    	{
    		temp = link;
    		link = link->next;
    		delete temp;
    		temp = 0;
    	}
    	
    	return(0);
    }
    ?

  4. #4
    Carnivore ('-'v) Hunter2's Avatar
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    2,879
    Something to that effect, yes. Although, you may want to change your loop condition to while(link). Since all nodes are dynamically allocated, they won't be automatically cleaned up when your program goes out of scope - so you have to do it yourself.
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  5. #5
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    Thank ya. I wasn't sure how to check if all the nodes were being deleted, so I'll take your while() loop on faith.

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