How hard is LeetCode 2956. Find Common Elements Between Two Arrays?

LeetCode 2956. Find Common Elements Between Two Arrays is rated Easy on LeetCode.

What is the time complexity of LeetCode 2956. Find Common Elements Between Two Arrays?

The Python solution on this page runs in O(n + m).

What is the space complexity of LeetCode 2956. Find Common Elements Between Two Arrays?

The Python solution on this page uses O(n + m) auxiliary space.

What topics does LeetCode 2956. Find Common Elements Between Two Arrays cover?

LeetCode 2956. Find Common Elements Between Two Arrays is tagged Array and Hash Table on LeetCode.

Find Common Elements Between Two Arrays — LeetCode 2956 Python Solution

EasyArrayHash Table

Problem: #2956
Pattern: Hash Map
Reading time: 2 min
Source: leetcode.com

The problem

You are given two integer arrays nums1 and nums2 of sizes n and m, respectively. Calculate the following values: answer1 : the number of indices i such that nums1[i] exists in nums2.

Python solution

Python

class Solution:
    def findIntersectionValues(self, nums1: List[int], nums2: List[int]) -> List[int]:
        s1, s2 = set(nums1), set(nums2)
        return [sum(x in s2 for x in nums1), sum(x in s1 for x in nums2)]

Complexity

Measure	Complexity
Time	O(n + m)
Space	O(n + m) auxiliary

Pattern: Hash Map

Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 2956. Find Common Elements Between Two Arrays is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Hash Table.

The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.

Frequently asked questions

How hard is LeetCode 2956. Find Common Elements Between Two Arrays?: LeetCode 2956. Find Common Elements Between Two Arrays is rated Easy on LeetCode.
What is the time complexity of LeetCode 2956. Find Common Elements Between Two Arrays?: The Python solution on this page runs in O(n + m).
What is the space complexity of LeetCode 2956. Find Common Elements Between Two Arrays?: The Python solution on this page uses O(n + m) auxiliary space.
What topics does LeetCode 2956. Find Common Elements Between Two Arrays cover?: LeetCode 2956. Find Common Elements Between Two Arrays is tagged Array and Hash Table on LeetCode.