Working with Graphs & Trees

What tree traversal order is used in this serialization format?

function serialize(root) {
  if (!root) return 'null';
  return `${root.value},${serialize(root.left)},${serialize(root.right)}`;
}

function deserialize(data) {
  const values = data.split(',');
  let index = 0;
  
  function dfs() {
    if (values[index] === 'null') {
      index++;
      return null;
    }
    const node = { value: parseInt(values[index++]), left: null, right: null };
    node.left = dfs();
    node.right = dfs();
    return node;
  }
  
  return dfs();
}

Inorder
Preorder
This uses preorder traversal for serialization because: 1) Processes root before children (root, left, right), 2) Enables straightforward recursive deserialization, 3) Maintains tree structure information implicitly, 4) Uses null markers to indicate missing children, 5) Preserves enough information to reconstruct tree, 6) Requires only single pass through data for deserialization, 7) Common in binary tree serialization formats, 8) Efficient for both serialization and deserialization operations.
Postorder
Level-order

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