Class Solution


  • public class Solution
    extends Object
    995 - Minimum Number of K Consecutive Bit Flips.

    Hard

    You are given a binary array nums and an integer k.

    A k-bit flip is choosing a subarray of length k from nums and simultaneously changing every 0 in the subarray to 1, and every 1 in the subarray to 0.

    Return the minimum number of k-bit flips required so that there is no 0 in the array. If it is not possible, return -1.

    A subarray is a contiguous part of an array.

    Example 1:

    Input: nums = [0,1,0], k = 1

    Output: 2

    Explanation: Flip nums[0], then flip nums[2].

    Example 2:

    Input: nums = [1,1,0], k = 2

    Output: -1

    Explanation: No matter how we flip subarrays of size 2, we cannot make the array become [1,1,1].

    Example 3:

    Input: nums = [0,0,0,1,0,1,1,0], k = 3

    Output: 3

    Explanation:

    Flip nums[0],nums[1],nums[2]: nums becomes [1,1,1,1,0,1,1,0]

    Flip nums[4],nums[5],nums[6]: nums becomes [1,1,1,1,1,0,0,0]

    Flip nums[5],nums[6],nums[7]: nums becomes [1,1,1,1,1,1,1,1]

    Constraints:

    • 1 <= nums.length <= 105
    • 1 <= k <= nums.length
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • minKBitFlips

        public int minKBitFlips​(int[] nums,
                                int k)