left and right to 0, and max_length to 0 to keep track of the maximum length of the window.right pointer to iterate through the array.k is greater than 0, decrement k.k is 0 and a zero is encountered, increment the left pointer until a zero is discarded from the window.max_length with the maximum of max_length and the current window size (right - left + 1).max_length as the result.