Storing Binary Tree into an array

Question

I attempting to store a binary tree into an array with the code below:

public void inorderArray(int[] array)  {
       inorderArray(root, array, 0);
}

private static Integer inorderArray(TreeNode root, int[] array, int index) { 
    // an inorder traversal that stores the items in array
    if(root == null){return index;}

    inorderArray(root.left, array, index);
    array[index++] = root.key;
    inorderArray(root.right, array, index);

    return index;
}

I keep getting [94, 95, 0, 0, 0, 0, 0, 0, 0, 0], and its not in order either.

I have no idea what I am doing wrong. Any help is appreciated.

as a side note - no need to return Integer, just int would suffice. — Ousmane D.
– Ousmane D., Commented Nov 5, 2017 at 18:53

janos · Accepted Answer · 2017-11-05 18:58:24Z

2

You are not using the return value. And you need to use it, because the modification in index++ would never leave the scope of the function.

private static int inorderArray(TreeNode root, int[] array, int index) {
    if (root == null) {
        return index;
    }

    index = inorderArray(root.left, array, index);
    array[index++] = root.key;
    index = inorderArray(root.right, array, index);
    return index;
}

answered Nov 5, 2017 at 18:58

janos

126k31 gold badges242 silver badges253 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Storing Binary Tree into an array

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related