LC-3191 Medium LeetCode

3191. Minimum Operations to Make Binary Array Elements Equal to One I

Array Bit Manipulation Queue Sliding Window Prefix Sum

Read the full problem statement on LeetCode.

Difficulty: medium Acceptance: 81% Topics: Array, Bit Manipulation, Queue, Sliding Window, Prefix Sum

Reading material

Arrays & Hashing 12 min Bit Manipulation 10 min Stacks & Queues 11 min

Reference solution (spoiler · python)

# Time:  O(n)
# Space: O(1)

# greedy
class Solution(object):
    def minOperations(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        result = 0
        for i in xrange(len(nums)-2):
            if nums[i]:
                continue
            nums[i+1] ^= 1
            nums[i+2] ^= 1
            result += 1
        return result if nums[-2] == nums[-1] == 1 else -1

Solution from kamyu104/LeetCode-Solutions · MIT