Class Solution
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
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Constructor Summary
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Method Summary
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Constructor Details
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Solution
public Solution()
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Method Details
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minKBitFlips
public int minKBitFlips(int[] nums, int k)
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