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LeetCode solutions

1037. Minimum Number of K Consecutive Bit Flips

My accepted Python solution to LeetCode problem 1037, Minimum Number of K Consecutive Bit Flips, running in 255ms.

  • Difficulty: Hard
  • Python
  • Runtime 255ms
  • Memory 22.4MB

Read the problem on LeetCode View on GitHub

The problem statement is LeetCode’s and stays on their site. What follows is my accepted solution.

Python

Accepted on LeetCode — runtime 255ms, memory 22.4MB, accepted 2026-01-01.

python
class Solution:
    def minKBitFlips(self, nums: List[int], k: int) -> int:
        n = len(nums)
        flips = 0
        flip_queue = []  # Stores ending indices of active flips
        
        for i in range(n):
            # Remove flips that have ended
            while flip_queue and flip_queue[0] <= i:
                flip_queue.pop(0)
            
            # Current effective value
            current = nums[i] ^ (len(flip_queue) % 2)
            
            if current == 0:
                # Need to flip
                if i + k > n:
                    return -1
                flips += 1
                flip_queue.append(i + k)
        
        return flips

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