[Python] Tree Constructor
Bob Alice
1204

For Tree problems, we are usually given the tree input as a List, which makes it hard if we want to debug our program. I wrote a simple tree constructor program which returns the root of the tree, which you can pass into your function.

def tree_constructor(node_list: List[int]) -> TreeNode:
    root = TreeNode(node_list[0])
    curr = [root]
    ptr = 1

    while ptr < len(node_list):
        curr2 = []
        for c in curr:
            if node_list[ptr] is not None:
                new = TreeNode(node_list[ptr])
                c.left = new
                curr2.append(new)
            ptr += 1
            if node_list[ptr] is not None:
                new = TreeNode(node_list[ptr])
                c.right = new
                curr2.append(new)
            ptr += 1
        curr = curr2
    return root
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