ML Questions:

• If loss flactuates, what should you do with learning rate?
• Range of cosine similarity
• if we increase depth of tree, what would be the inference time increase?

Coding question:

You are given an integer array parent representing a forest of rooted trees with n nodes, where parent[i] is the parent of the i-th node.

If parent[i] == i, then node i is the root of a tree.

Otherwise, parent[i] < i, meaning that the parent always has a smaller index.

Every node has exactly one parent, except the root.

You are also given an integer nodeToDelete, representing a node to delete.

Your task is to delete nodeToDelete and all of its descendants from the forest.
Deletion is done in-place by setting parent[x] = -1 for every deleted node x.

Return the updated parent array.

Solution:

def deleteSubtree(parent, nodeToDelete):
    n = len(parent)
    
    # Mark the root node of the subtree itself
    parent[nodeToDelete] = -1  
    
    for i in range(n):
        if parent[i] == -1:  # already deleted
            continue

        j = i
        # Walk upward until root or deletion target
        while parent[j] != j and parent[j] != -1 and parent[j] != nodeToDelete:
            j = parent[j]

        # If we reached nodeToDelete, delete this node too
        if parent[j] == nodeToDelete:
            parent[i] = -1

    return parent