322. Max Consecutive Ones III

Maintain a window with at most k zeros. Expand right; when zeros exceed k, shrink left.

Approach

1. Sliding window [left, right].
2. Expand right, count zeros in window.
3. When zeros > k, shrink left until zeros <= k.
4. Track max window size.

Complexity

• Time: O(n)
• Space: O(1)

class Solution {
    public int longestOnes(int[] nums, int k) {
        int left = 0, zeros = 0, maxLen = 0;
        for (int right = 0; right < nums.length; right++) {
            if (nums[right] == 0) {
                zeros++;
            }
            while (zeros > k) {
                if (nums[left] == 0) {
                    zeros--;
                }
                left++;
            }
            maxLen = Math.max(maxLen, right - left + 1);
        }
        return maxLen;
    }
}