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Problem solution · Python

Design Task Manager

Design Task Manager: a Python solution using direct simulation. Learn the idea, check the complexity, and read the full code, with credit to walkccc LeetCode Solutions.

Technique
Direct simulation
Source
walkccc LeetCode Solutions
Length
47 lines
Start with the idea.

Try the problem first. If you get stuck, read the approach below, then write your own solution. The full code is at the bottom.

Approach

Direct simulation

For Design Task Manager, the implementation follows the problem’s operations directly while maintaining only the state needed for the next decision.

  1. Translate each rule into one explicit state update.
  2. Maintain the invariant after every processed item.
  3. Return the accumulated state once all relevant input has been handled.

Code notes

  • 47 lines of Python from the credited upstream file 3408.py.
  • The implementation visibly relies on sequence storage.
  • No explicit loop blocks detected.

Complexity

Count the number and nesting of passes over the input, then include the maintained containers in the memory estimate.

Check the problem constraints before deciding whether this complexity will pass.

Source

Code and credit

This code comes from walkccc LeetCode Solutions by P.-Y. Chen (walkccc) and is used under the MIT licence.

Open problem ↗Original source ↗
Full codeDesign Task Manager · PythonPython
Use this to learn the idea, then write your own version.
from dataclasses import dataclassfrom sortedcontainers import SortedDict, SortedSet  @dataclass(frozen=True)class Task:  userId: int  taskId: int  priority: int   def __lt__(self, other):    if self.priority == other.priority:      return self.taskId > other.taskId    return self.priority > other.priority  class TaskManager:  def __init__(self, tasks: list[list[int]]):    self.taskMap = SortedDict()  # {taskId: Task}, keeps tasks sorted by taskId    self.taskSet = SortedSet()  # Stores tasks sorted by priority and taskId    for task in tasks:      self.add(task[0], task[1], task[2])   def add(self, userId: int, taskId: int, priority: int) -> None:    task = Task(userId, taskId, priority)    self.taskMap[taskId] = task    self.taskSet.add(task)   def edit(self, taskId: int, newPriority: int) -> None:    task = self.taskMap[taskId]    self.taskSet.remove(task)    editedTask = Task(task.userId, taskId, newPriority)    self.taskSet.add(editedTask)    self.taskMap[taskId] = editedTask   def rmv(self, taskId: int) -> None:    task = self.taskMap[taskId]    self.taskSet.remove(task)    del self.taskMap[taskId]   def execTop(self):    if not self.taskSet:      return -1    task = self.taskSet.pop(0)    del self.taskMap[task.taskId]    return task.userId

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