g0901_1000.s0995_minimum_number_of_k_consecutive_bit_flips

Class Solution

java.lang.Object

g0901_1000.s0995_minimum_number_of_k_consecutive_bit_flips.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 Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int	minKBitFlips(int[] nums, int k)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

minKBitFlips

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