LC-2869 Easy LeetCode

2869. Minimum Operations to Collect Elements

Read the full problem statement on LeetCode.

Difficulty: easy Acceptance: 61% Topics: Array, Hash Table, Bit Manipulation

Reading material

Arrays & Hashing 12 min Bit Manipulation 10 min

Reference solution (spoiler · python)

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

# hash table
class Solution(object):
    def minOperations(self, nums, k):
        """
        :type nums: List[int]
        :type k: int
        :rtype: int
        """
        lookup = [False]*k
        for i in reversed(xrange(len(nums))):
            if nums[i] > len(lookup) or lookup[nums[i]-1]:
                continue
            lookup[nums[i]-1] = True
            k -= 1
            if not k:
                break
        return len(nums)-i

Solution from kamyu104/LeetCode-Solutions · MIT