2244.Minimum Rounds to Complete All Tasks

tags: Medium,Array,Hash Table,Greedy,Counting

2244. Minimum Rounds to Complete All Tasks

題目描述

You are given a 0-indexed integer array tasks, where tasks[i] represents the difficulty level of a task. In each round, you can complete either 2 or 3 tasks of the same difficulty level.

Return the minimum rounds required to complete all the tasks, or -1 if it is not possible to complete all the tasks.

範例

Example 1:

Input: tasks = [2,2,3,3,2,4,4,4,4,4]
Output: 4
Explanation: To complete all the tasks, a possible plan is:
- In the first round, you complete 3 tasks of difficulty level 2. 
- In the second round, you complete 2 tasks of difficulty level 3. 
- In the third round, you complete 3 tasks of difficulty level 4. 
- In the fourth round, you complete 2 tasks of difficulty level 4.  
It can be shown that all the tasks cannot be completed in fewer than 4 rounds, so the answer is 4.

Example 2:

Input: tasks = [2,3,3]
Output: -1
Explanation: There is only 1 task of difficulty level 2, but in each round, you can only complete either 2 or 3 tasks of the same difficulty level. Hence, you cannot complete all the tasks, and the answer is -1.

Constraints:

• 1 <= tasks.length <= 10⁵
• 1 <= tasks[i] <= 10⁹

解答

Python

class Solution:
    def minimumRounds(self, tasks: List[int]) -> int:
        counter = Counter(tasks)
        ans = 0
        
        for cnt in counter.values():
            if cnt < 2:
                return -1
            else:
                ans += (cnt + 2) // 3

        return ans

寫到這靈感就來了

class Solution:
    def minimumRounds(self, tasks: List[int]) -> int:
        return -1 if 1 in Counter(tasks).values() else sum((cnt + 2) // 3 for cnt in Counter(tasks).values())

KobeJan 4, 2023

Reference

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