Merge Two 2D Arrays by Summing Values — LeetCode 2570 Python Solution

The problem

You are given two 2D integer arrays nums1 and nums2. nums1[i] = [idi, vali] indicate that the number with the id idi has a value equal to vali.

Example

Input

nums1 = [[1,2],[2,3],[4,5]], nums2 = [[1,4],[3,2],[4,1]]

Output

[[1,6],[2,3],[3,2],[4,6]]

Explanation

The resulting array contains the following:

Python solution

class Solution:
    def mergeArrays(
        self, nums1: List[List[int]], nums2: List[List[int]]
    ) -> List[List[int]]:
        cnt = Counter()
        for i, v in nums1 + nums2:
            cnt[i] += v
        return sorted(cnt.items())

Complexity

Pattern: Two Pointers

Use the order already in the input to discard half the search space at every step. LeetCode 2570. Merge Two 2D Arrays by Summing Values is filed here because LeetCode tags it Two Pointers, which is the vocabulary this hub collects.

The two pointers guide has the Python template for the pattern and the 201 LeetCode problems that use it.

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