[Algo] 625. Longest subarray contains only 1s

Given an array of integers that contains only 0s and 1s and a positive integer k, you can flip at most k 0s to 1s, return the longest subarray that contains only integer 1 after flipping.

Assumptions:

1. Length of given array is between [1, 20000].

2. The given array only contains 1s and 0s.

3. 0 <= k <= length of given array.

Example 1:

Input: array = [1,1,0,0,1,1,1,0,0,0], k = 2

Output: 7

Explanation: flip 0s at index 2 and 3, then the array becomes [1,1,1,1,1,1,1,0,0,0], so that the length of longest subarray that contains only integer 1 is 7.

Example 2:

Input: array = [1,1,0,0,1,1,1,0,0,0], k = 0

Output: 3

Explanation: k is 0 so you can not flip any 0 to 1, then the length of longest subarray that contains only integer 1 is 3.

public class Solution {
  public int longestConsecutiveOnes(int[] nums, int k) {
    // Write your solution here
    int i = 0;
    int start = 0;
    int count = 0;
    int result = 0;
    while (i < nums.length) {
      if (nums[i] == 0) {
        count += 1;
      }
      while (count > k) {
        if (nums[start] == 0) {
          count -= 1;
        }
        start += 1;
      }
      i += 1;
      result = Math.max(result, i - start);
    }
    return result;
  }
}