Data Structures

Displayed Nodes in a Tree View

Difficulty

Asked at Jane Street

Theory: Data Structures You Implement, Not Import

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Available in Python and C++. You are solving it in Python. Switch to C++

x xxxx xxxx xxxxx x xxxxx xxxxxxxxx, xxxx xx x xxxx'x xxxxx xxxxxxx xx xxxx xxx xxxxxx. xxx xxxx xxxxxxx xxxxx xx xxxx xx, xxx xxx xxxx xxxx xxxx xxxxxx xx xxx xxxx xxxxxx xxxx xxxxxxxxx xx xxxx xx xxxxxxx. xxxxxxxxxx xxx xxxxx xxx xxxxxxx xxx xxx xxxx, xx xxx xxxx xxxx xxx xxxxxxx xxxxxx xxxx xxxxxxx xxxxx xxxx xxxxxx. xxx xxxx xxx (x) xxxxx, xxxxxxxx (x) xx (x - x). xxxxxxx[x] xx xxx xxxxxx xx xxxx x, xxx xxxxxxx xxx xxxxx xx -x: xxxx xxxx xx xxx xxxx. xxx xxxx xxxx xxx xx xxxx x. xx xxx xxxxx xx xxxx xx xxxxxxxx. x xxxx xx xxxxxxxxx xxxx xx xxxxx xxx xx xxxxx xx xxxx: xx xx xxxxxxxx; xx xx xx xxxxxxxx xx x xxxxxxxx xxxx (xxx xxxxxx, xxx xxxxxx'x xxxxxx, xxx xx xx xx xx xxx xxxx); xx xx x xxxxxxx xx x xxxxxxxx xxxx: xx xxx xxx xxxx xxxxxx xx x xxxxxxxx xxxx. xx xxxxxxxxx x xxxx xxxxx xxx xxxx, xxxxx xxxxx xxxxx xx xxx xxxxxx, xxx xxxxx xxxx xx xxx xxxx xx xxx xxxx. xx xxxx xxx xxxx xxx xxx xxxxxxxx, xxx xx xxxx xxx xxxx xxx xxxxxxxx xx xxx xxxxxxxxx. xxx xxxx xxx xx xxxxxxxx. xxxxxxxxx x xxxxx xxxxxxxx(xxxxxxx) xxxx xxxxx xxxxxxx: xxxxxx(x): xxxxxx xxxx x. xxxxxxxxx x xxxx xxxx xx xxxxxxx xxxxxxxx xxxx xxxxxxx. xxxxxxxx(x): xxxxxxxx xxxx x. xxxxxxxxxxx x xxxx xxxx xx xxx xxxxxxxx xxxx xxxxxxx. xxxxx(): xxxxxx xxx xxxxxx xx xxxxxxxxx xxxxx. xxxxxxxxx(): xxxxxx xxx xxxxxxxxx xxxxx xx xxxxxxxxx xxxxx. xxx xxxxx xxxxx xxxx xxxxx xxxxxxx xxx xxx_xxx(xxxxxxx, xxx) xxxxxx xxxxxxx xx xxx xxxxxxxx (xx xxx xxxxxx xx). xxxx xx xx ("xxxxxx", x), ("xxxxxxxx", x), ("xxxxxxxxx",) xx ("xxxxx",). xxx xxxxxx xxxxxxx x xxxx: xxx xxxx xx xxxxx xxxxxxxxx() xxxxxx, xx xxxxx, xxx xxx xxxx xx xxxxx xxxxx() xxxxxx, xx xxxxx. xxxxxxxx # x # / | # x x x # / # x x x # / # x x xxxxxxx = [-x, x, x, x, x, x, x, x, x] xxx_xxx(xxxxxxx, [("xxxxxx", x), ("xxxxxxxxx",), ("xxxxx",), ("xxxxxx", x), ("xxxxxxxxx",), ("xxxxx",), ("xxxxxxxx", x), ("xxxxxxxxx",), ("xxxxx",)]) # ([[x, x, x, x, x], [x, x, x, x, x, x, x], [x, x, x]], [x, x, x]) # xxxxxxxxx x xxxxx x, xxx xxxxxxx x xxx xxx xxxxxxxxx x, x xxx x. # xxxx x xx x xxxxxxx xx xxx xxxxxxxx x, xx xx xxxxx xxxxxx. xxx_xxx(xxxxxxx, [("xxxxxx", x), ("xxxxxxxxx",), ("xxxxxx", x), ("xxxxxxxxx",), ("xxxxxxxx", x), ("xxxxxxxxx",), ("xxxxxxxx", x), ("xxxxx",)]) # ([[x, x, x, x], [x, x, x, x], [x]], [x]) # xxxxxxxxx x xxxxx xxx xxxxxxxx x xxx x xxx xxx xxx xxxxxxxx x xxx x. # xxxxxxxxx xxx xxxx xxxxx xxxx xxx xxxx. xxxxxxxxxxx (x xx x xx xx^x). xxx xxxx xx xx xxxx xx xxxxxx xxxx. xx xx (x xxxxx xx^x) xxxxxxxxxx. xxxxx x xx x xxxxx xxxx. xxxxx() xxxx xxxx (x(x)) xxxx. xxxxxx xxx xxxxxxxx xxx xxxx xxxx xxxxxxxxxxxx xx xxx xxxxx xx xxx xxxx. xxxxxxxxx() xxxxxx xxxx xxxx xxxxx xx xxx xxxx xx xxx xxxxxx, xxx xxx xxxx xx xxx xxxx: xxx xxxxx xxx xxx xxxx xxxxx xx x xxxxx xxxx xxxx xxxx x xxx xxxxx xxxxxxxx. xxx xxxxxxx xxxxxx xxxxx xxxx xxxxxxxxx xx xxxxx xxxxxxxx xxx xxx xxx xxx xxxxx xxxxx xxxxx xxxxxx. xxxxxxx xxx xxxxxxxxx xxx xxx xxxxx xx xxxx xxxxx xx xxx xxxx. x xxxx xxx xxxx xxxxxxxx xx xxxxxxxxx xx xxxxxxxx, xxx x xxxxxx xxxx xxxxxxx xxx xxxxxxxxx xxxx xxx xx x xxxx. x xxxxxx xxxx xxxxxx xxxxx xxxxx xx xxx xxxxxx xx xxx xxxx. xx x++ xxxxx xxxxxxxx { xxxxxx: xxxxxxxx xxxxxxxx(xxxxx xxx::xxxxxx<xxx>& xxxxxxx); xxxx xxxxxx(xxx x); xxxx xxxxxxxx(xxx x); xxxx xxxx xxxxx() xxxxx; xxx::xxxxxx<xxx> xxxxxxxxx() xxxxx; }; xxx xxxxxxxx'x xxx_xxx xxxxx xxx xx {"xxxxxx", x}, {"xxxxxxxx", x}, {"xxxxxxxxx"} xxx {"xxxxx"}, xxx xxxxxxx x xxx::xxxx<xxx::xxxxxx<xxx::xxxxxx<xxx>>, xxx::xxxxxx<xxxx xxxx>>: xxx xxxxxxxxx xxxxx, xxxx xxx xxxxxx. xxx x++ xxxxxxxxxxx xxxxx xxx xxxxxx: x xxxx xx (xx^x) xxxxx xxx xx xx (x.x xxxxx xx^x) xxxxxxxxxx.

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Language:

Python 3.12 C++23

run_ops

from typing import Any


class TreeView:
    def __init__(self, parents: list[int]) -> None:
        """..."""
        # ...
        pass

    def select(self, v: int) -> None:
        """..."""
        # ...
        pass

    def deselect(self, v: int) -> None:
        """..."""
        # ...
        pass

    def count(self) -> int:
        """..."""
        # ...
        pass

    def displayed(self) -> list[int]:
        """..."""
        # ...
        pass


# ...
def run_ops(parents: list[int], ops: list[tuple[Any, ...]]) -> tuple[list[list[int]], list[int]]:
    view = TreeView(parents)
    lists, counts = [], []
    for op in ops:
        if op[0] == "select":
            view.select(op[1])
        elif op[0] == "deselect":
            view.deselect(op[1])
        elif op[0] == "displayed":
            lists.append(view.displayed())
        else:
            counts.append(view.count())
    return lists, counts

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