CODEWITHSUNDEEP
cvisual-c++-6
Tran Hoai Nam
Tran Hoai Nam

Reputation: 1363

insert values into a binary search tree in C?

I have a .h file that contains my struct and I must NOT edit this file:

struct KnightTree 
{
    int key;
    int level; 
    int balance;            //will be used in AVL only, and be ignored in other cases.
    KnightTree* pLeftChild;
    KnightTree* pRightChild;
};

And a .cpp file that I write my code here, I've written a code to insert 2 values (key and level) into the BST:

void BSTinsert(KnightTree* tree, int k, int lvl)
{
    KnightTree* newnode;
    if (tree == NULL)
    {
        newnode->key=k;
        newnode->level=lvl;
        newnode->pLeftChild=NULL;
        newnode->pRightChild=NULL;
        tree = newnode;
    }
    else
    {
        if (tree->key > k)
            BSTinsert(tree->pLeftChild,k,lvl);
        else if (tree->key <= k)
            BSTinsert(tree->pRightChild,k,lvl);
    }
}

But when I run it, the console "thinks" itself for about 3 seconds and error pop-up said "exe has stop working" so I have to close the program. I think's simple but I'm kinda confused now... I'm using Visual C++ 6.0 (I have to use this old version...)

Thank you guys!

Upvotes: 0

Views: 141

Answers (1)

SomeWittyUsername
SomeWittyUsername

Reputation: 18358

You have at least 2 major problems:

  1. You do not allocate memory for your newnode, so by addressing it you just create memory corruption.
  2. You do not attach your newly created node to the tree, assigning tree = newnode doesn't create the necessary link to the tree.

Proceed from fixing these 2 issues.

And one more thing: have you tried to actually debug it before posting the question here?

Upvotes: 2

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