[LeetCode] Problem 1004 - Max Consecutive Ones III

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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

No.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.

No.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

Code

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public int longestOnes(int[] A, int K) {
    int max = 0;
    int start = 0;
    int end = 0;
    int zero = 0;

    while (end < A.length) {
        if (A[end] == 0)
            zero++;

        while (zero > K) {
            if (A[start] == 0)
                zero--;

            start++;
        }

        max = Math.max(max, end - start + 1);
        end++;
    }

    return max;
}