Skip to content

2248. Intersection of Multiple Arrays

Difficulty Topics

Description

Given a 2D integer array nums where nums[i] is a non-empty array of distinct positive integers, return the list of integers that are present in each array of nums sorted in ascending order.

 

Example 1:

Input: nums = [[3,1,2,4,5],[1,2,3,4],[3,4,5,6]]
Output: [3,4]
Explanation: 
The only integers present in each of nums[0] = [3,1,2,4,5], nums[1] = [1,2,3,4], and nums[2] = [3,4,5,6] are 3 and 4, so we return [3,4].

Example 2:

Input: nums = [[1,2,3],[4,5,6]]
Output: []
Explanation: 
There does not exist any integer present both in nums[0] and nums[1], so we return an empty list [].

 

Constraints:

  • 1 <= nums.length <= 1000
  • 1 <= sum(nums[i].length) <= 1000
  • 1 <= nums[i][j] <= 1000
  • All the values of nums[i] are unique.

Solution

intersection-of-multiple-arrays.py
class Solution:
    def intersection(self, nums: List[List[int]]) -> List[int]:
        n = len(nums)
        count = Counter()

        for arr in nums:
            for x in arr:
                count[x] += 1

        res = []

        for k, v in count.items():
            if v == n:
                res.append(k)

        return sorted(res)