[LeetCode] 2206. Divide Array Into Equal Pairs (Python)

 

 

난이도: Easy

Problem Description

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You are given an integer array nums consisting of 2 * n integers.

You need to divide nums into n pairs such that:

• Each element belongs to exactly one pair.
• The elements present in a pair are equal.

Return true if nums can be divided into n pairs, otherwise return false.

 

Problem Example

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Example 1:

Input: nums = [3,2,3,2,2,2]
Output: true
Explanation: 
There are 6 elements in nums, so they should be divided into 6 / 2 = 3 pairs.
If nums is divided into the pairs (2, 2), (3, 3), and (2, 2), it will satisfy all the conditions.

Example 2:

Input: nums = [1,2,3,4]
Output: false
Explanation: 
There is no way to divide nums into 4 / 2 = 2 pairs such that the pairs satisfy every condition.

 

Constraints

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• nums.length == 2 * n
• 1 <= n <= 500
• 1 <= nums[i] <= 500

 

✏️ Solution

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class Solution:
    def divideArray(self, nums: List[int]) -> bool:
        nums_count = Counter(nums)
        return all(cnt % 2 == 0 for cnt in nums_count.values())

단순히 생각해보면 nums의 요소 중 같은 요소들을 세었을 때 짝수개 만큼 있으면 조건을 만족하면서 pair를 만들 수 있다.

 

따라서 Counter함수를 통해 nums의 요소를 세었다.

 

이 때, nums_count.value()에 값들 중 홀수가 있으면 False를 return하고 모두 짝수라면 True를 반환하면 된다.

 

 

⚙️ Runtime & Memory

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문제: 2206. Divide Array Into Equal Pairs

 

깃허브: github

algorithmPractice/LeetCode/2308-divide-array-into-equal-pairs at main · laewonJeong/algorithmPractice