How should I practice Nested Todo List?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Notion phone screen and onsite interview problems in FastPrep.

Is Nested Todo List associated with Notion?

FastPrep tags this as a Notion phone screen and onsite interview coding practice problem when the problem catalog has that company and stage context.

Nested Todo List

Notion● MediumFULLTIMEPHONE SCREENONSITE INTERVIEW

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Problem statement

Process operations against an initially empty nested todo list. Items form an ordered forest.

["ADD", id, parentId, text] adds a pending item. A parentId of - makes it a root; otherwise it becomes the newest child of that parent.
["TOGGLE", id] switches that item between PENDING and DONE. Toggling one item does not change descendants or ancestors.
["GET", id] returns id|parentId|status|text.
["RENDER"] returns every item in preorder. Each line is depth|id|status|text, roots and siblings retain insertion order, and lines are joined by a newline.

Return the values produced by GET and RENDER operations in order.

Function

runNestedTodoList(operations: String[][]) → String[]

Examples

Example 1

operations = [["ADD","1","-","Plan"],["ADD","2","1","Draft"],["ADD","3","1","Review"],["TOGGLE","2"],["GET","2"],["RENDER"]]return = ["2|1|DONE|Draft","0|1|PENDING|Plan\n1|2|DONE|Draft\n1|3|PENDING|Review"]

The two children retain insertion order. Toggling item 2 changes only that item.

Constraints

1 <= operations.length <= 20000.
IDs are unique non-empty strings containing neither | nor whitespace.
Every non-root parent exists before its child is added.
Every GET and TOGGLE references an existing item.
Text is non-empty and contains neither | nor a newline.
The total number of rendered item lines is at most 200000.