LC-1679 Medium LeetCode

1679. Max Number of K-Sum Pairs

Read the full problem statement on LeetCode.

Difficulty: medium Acceptance: 56% Topics: Array, Hash Table, Two Pointers, Sorting

Reading material

Arrays & Hashing 12 min Two Pointers 9 min Sorting 13 min

Reference solution (spoiler · python)

# Time:  O(n)
# Space: O(n)

import collections


class Solution(object):
    def maxOperations(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: int
        """
        count = collections.Counter()
        result = 0
        for x in nums:
            if k-x in count and count[k-x]:
                count[k-x] -= 1
                result += 1
            else:
                count[x] += 1
        return result

Solution from kamyu104/LeetCode-Solutions · MIT