#🔒 Design Task Manager

100 messages · Page 1 of 1 (latest)

errant plume
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Leetcode 3408 question

class TaskManager:

    def __init__(self, tasks: List[List[int]]):
        self.dict1=[]
        self.task=tasks[:]
        for i,j,k in self.task:
            heapq.heappush(self.dict1,(-k,-j))
        self.dict3={} 
        for i,j,k in self.task:
            self.dict3[j]=k
        self.dict2={}
        for i,j,k in self.task:
            self.dict2[j]=i
        self.set1=set()
          

    def add(self, userId: int, taskId: int, priority: int) -> None:
        heapq.heappush(self.dict1,(-priority,-taskId))
        self.dict3[taskId]=priority
        self.dict2[taskId]=userId
        if taskId in self.set1:
            self.set1.discard(taskId)
        

    def edit(self, taskId: int, newPriority: int) -> None:
        heapq.heappush(self.dict1,(-newPriority,-taskId))
        self.dict3[taskId]=newPriority

    def rmv(self, taskId: int) -> None:
        self.set1.add(taskId)
      

    def execTop(self) -> int:
        if not self.dict1:
            return -1
        (x,y)=heapq.heappop(self.dict1)
        while -y in self.set1 or self.dict3[-y]!=-x:
            if not self.dict1:
                return -1
            (x,y)=heapq.heappop(self.dict1)
        # heapq.heappush(self.dict1,(x,y))
        return self.dict2[-y]
         
# Your TaskManager object will be instantiated and called as such:
# obj = TaskManager(tasks)
# obj.add(userId,taskId,priority)
# obj.edit(taskId,newPriority)
# obj.rmv(taskId)
# param_4 = obj.execTop()
image.png
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#

@errant plume

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hazy crescent
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hi there

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whats the issue? And how are you trying to solve it? Your variable naming makes it very heard to understand your solution

errant plume
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i just try to add the tasks into a maxheap called "dict1" that has priority com taskid

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for tracking of removed tasks i made a set

red horizon
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yeah your variable naming is really not very good. why are you naming your variables dict1, dict2, dict3 ? not to mention dict1 is not even a dictionary, but a list...

errant plume
#

yeah my bad

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let me telll you my approach did you understand the question

hazy crescent
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yes

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ik the question, i spent like 2 hrs yesterday on it

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lol

errant plume
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got it?

hazy crescent
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tell me your approach

errant plume
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i just add everything into maxheap while exceuting i just check whether its already removed or its value is not correct like that

hazy crescent
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yes go on, how are you implementing the init method?

errant plume
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just initializing the maxheap with the current tasks available

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and also assigning dictionaries to the taskid and their priority

hazy crescent
#

you insert into the heapq like this (negPriority, negTaskId) right?

errant plume
#

yeah

hazy crescent
errant plume
#

-priority,-taskid

hazy crescent
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ok

errant plume
hazy crescent
#

lets call the heapq as self.pq instead of dict1 shall we? it will help us avoid confusion

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and the taskId-priority dict as taskPriorityMap

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or taskPriorityDict whatever

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then what do you do in the init method?

errant plume
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and also taskid:userid for returning userid

hazy crescent
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cool

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what is that set?

errant plume
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that stores which tasks has removed

hazy crescent
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hmm I see trouble there

errant plume
# 
class TaskManager:

    def __init__(self, tasks: List[List[int]]):
        self.pq=[]
        self.task=tasks[:]
        for i,j,k in self.task:
            heapq.heappush(self.pq,(-k,-j))
        self.taskPriorityMap={} 
        for i,j,k in self.task:
            self.taskPriorityMap[j]=k
        self.taskUserMap={}
        for i,j,k in self.task:
            self.taskUserMap[j]=i
        self.removedtask=set()
          

    def add(self, userId: int, taskId: int, priority: int) -> None:
        heapq.heappush(self.pq,(-priority,-taskId))
        self.taskPriorityMap[taskId]=priority
        self.taskUserMap[taskId]=userId
        if taskId in self.removedtask:
            self.removedtask.discard(taskId)
        

    def edit(self, taskId: int, newPriority: int) -> None:
        heapq.heappush(self.pq,(-newPriority,-taskId))
        self.taskPriorityMap[taskId]=newPriority

    def rmv(self, taskId: int) -> None:
        self.removedtask.add(taskId)
      

    def execTop(self) -> int:
        if not self.pq:
            return -1
        (x,y)=heapq.heappop(self.pq)
        while -y in self.removedtask or self.taskPriorityMap[-y]!=-x:
            if not self.pq:
                return -1
            (x,y)=heapq.heappop(self.pq)
        # heapq.heappush(self.pq,(x,y))
        return self.taskUserMap[-y]
         
# Your TaskManager object will be instantiated and called as such:
# obj = TaskManager(tasks)
# obj.add(userId,taskId,priority)
# obj.edit(taskId,newPriority)
# obj.rmv(taskId)
# param_4 = obj.execTop()
hazy crescent
#

now your code is much more readable

errant plume
#

what was the problem can you find out please

hazy crescent
#

brb

errant plume
#

?

hazy crescent
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im back

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brb - be right back

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your init and add methods look solid

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hmm edit method looks correct too

red horizon
hazy crescent
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cos i like camelcase, its easier to type

red horizon
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it's not PEP compliant though

hazy crescent
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i dont give a F though xD

red horizon
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if you write camelcase variable names in python it's just gonna be an ugly mix because 99% of the libraries you use will have method names and variables named with snake case. i just don't think this is a good habit to pass on to other people

hazy crescent
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true that

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old habbits die hard

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the problem is in the execTop method prolly

red horizon
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rename the variables i, j, k in __init__ and x, y in execTop (which should be exec_top) to be descriptive too

hazy crescent
#

yeah that and the init method could be rewritten as:

        self.pq = []
        self.taskUserMap = {}
        self.taskPriorityMap = {}

        for task in tasks:
            self.pq.append((-task[2], -task[1]))
            self.taskUserMap[task[1]] = task[0]
            self.taskPriorityMap[task[1]] = task[2]
        heapq.heapify(self.pq)
        self.removedtask = set()
errant plume
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yeah all look good whats the proble,

red horizon
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use snake_case instead of camelCase for python variable names and functions:
task_user_map instead of taskUserMap etc.
otherwise you're just going to set yourself up for pain later

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if you ever want to collaborate with other people etc.

hazy crescent
#

+1

errant plume
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yeah

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this is painful than that

image.png
hazy crescent
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i think i found the issue

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im not sure

errant plume
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yeah say it

hazy crescent
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ohh ok

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got it

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@errant plume

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you are not adding the executed task to the removed set after popping it from the heap

errant plume
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one sec

hazy crescent
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lmk if it works

errant plume
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got it tq

image.png
hazy crescent
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hell yeah

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gg

errant plume
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how did you solve ?

hazy crescent
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i tried to maintain a single pq first like this (-P, -tId, uId)

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did not work obv

errant plume
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finally you got ?

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other than my approach

hazy crescent
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then I did something similar to what you have done

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except I did not maintain a removed set

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I just did self.taskPriorityMap[taskId] = None for removed tasks

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and my exec method is diff:

    def execTop(self) -> int:
        while self.pq:
            topTask = heapq.heappop(self.pq)
            if self.taskPriorityMap[-topTask[1]] == -topTask[0]:
                self.taskPriorityMap[-topTask[1]] = None
                return self.taskUserMap[-topTask[1]]
        return -1```
errant plume
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yeah got it

hazy crescent
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took me hours

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very interesting problem though

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from next sol onwards, try to name your vars properly

errant plume
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yeah tq

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did todays contest

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?

hazy crescent
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not yet, its a hard one

errant plume
#

3rd problem is little bit hard ngl backtracking

hazy crescent
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idk backtracking :(

errant plume
#

where are you from

hazy crescent
#

TN

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wbu

errant plume
#

chennao

hazy crescent
#

dm

vocal gladeBOT
#
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