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# Max Consecutive Ones III

Given an array `A` of 0s and 1s, we may change up to `K` values from 0 to 1.

Return the length of the longest (contiguous) subarray that contains only 1s. 

**Example 1:**

```
Input: A = [1,1,1,0,0,0,1,1,1,1,0], K = 2
Output: 6
Explanation: 
[1,1,1,0,0,1,1,1,1,1,1]
Bolded numbers were flipped from 0 to 1.  The longest subarray is underlined.
```

**Example 2:**

```
Input: A = [0,0,1,1,0,0,1,1,1,0,1,1,0,0,0,1,1,1,1], K = 3
Output: 10
Explanation: 
[0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,1,1,1,1]
Bolded numbers were flipped from 0 to 1.  The longest subarray is underlined.
```

**Note:**

1. `1 <= A.length <= 20000`
2. `0 <= K <= A.length`
3. `A[i]` is `0` or `1`&#x20;

```java
class Solution {
    public int longestOnes(int[] A, int K) {
        int zerosUsed = 0, max = 0;
        int start = 0, end = 0;
        while (end < A.length) {
            if (A[end] == 0)
                zerosUsed++;
            while (zerosUsed > K) {
                if (A[start] == 0)
                    zerosUsed--;
                start++;
            }
            max = Math.max(max, end - start + 1);
            end++;
        }
        return max;
    }
}
```