ekan5h / avltree Goto Github PK

Line117:
height(head->left) >= height(head->right)

it should be relpaced with "height(head->left->left) >= height(head->left->right)"?

Similar to Line 124.

I found a case recently. which caused a segment fault.

Here is my test code.

#include<vector>
int main(){
    AVL<int> tree;
    vector<int> v;

    int x;
    while(cin >> x)
    {
        getchar();
        v.push_back(x);
        tree.insert(x);
    }
    for(auto &&x : v)
    {
        tree.remove(x);
    }
    return 0;
}

Here is my testcase.

tc.txt

Reproduce bug

Add your code in front of my code, compile and run with the following commands.

g++ mycode.cpp -o mycode
cat tc.txt | ./mycode

the rebalancing of the tree in the remove function right is done this way:

if(bal>1){
    if(x > head->left->key){
        return rightRotation(head);
}else{
    head->left = leftRotation(head->left);
    return rightRotation(head);
    }
}else if(bal < -1){
    if(x < head->right->key){
    return leftRotation(head);
}else{
    head->right = rightRotation(head->right);
    return leftRotation(head);
    }
}

This code doesn't always work. I think that

if(x > head->left->key)

should be replaced with

if(height(head->left) > height(head->right))

and the same applies for

if(x < head->right->key)

that should be replaced with

if(height(head->right) > height(head->left))

I was researching for an excercise I had to do and I think that this should work. I am a novice on github and I am only submitting this because I've seen another guy report (I think) the same problem. Let me know if this is helpful