Use in-order traversal to serialize.
Given in-order [2, 1, 4, 3, 5], you can't reconstruct the tree uniquely. You don't know where the root is or how the nodes are arranged.
You need to encode the structure, not just the values.
##### ###### ##### ### # # ### # # ###### ## ## ## ## ## ## ## # # # # # ## ##### #### ##### # # # # # # # #### ## # ## ## ## ## # # # # # ## ## # ###### ## ### # ### # ######
$ curl repovive.com/roadmaps/pattern-22/trees/serialize-and-deserialize-binary-tree-why-naive-fails
░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░███████████████████████████████████████████████████████████████████████████████████████████████████