Command Execution System with Tag-Based Undo

Implement a command execution system that records commands in time order and supports undo operations. You need to implement two functions: execute(command: str, tags: List[str]) -> None undo(tag: Optional[str] = None) -> str Rules: Each call to execute executes a command command and associates it with a list of tags (a command may have multiple tags). Commands are ordered by execution time (later = more recent). undo() with no tag undoes the most recently executed command. undo(tag) with a tag undoes the most recent command that has this tag (scan history from newest to oldest and pick the first command containing that tag). A command can be undone at most once; once undone it must not be returned by any future undo. undo(...) returns the command string that was undone. Design appropriate data structures to support these operations efficiently. Constraints: Total number of execute and undo calls up to 1e5 Each command has k tags, where 0 <= k <= 10 command is an opaque string identifier Example: execute("A", ["x"]) execute("B", ["y"]) execute("C", ["x","y"]) undo() returns "C" undo("x") returns "A" undo("y") returns "B" Example Input execute A x execute B y execute C x y undo undo x undo y Output C A B