1004.Max-Consecutive-Ones-III

1004. Max Consecutive Ones III

题目地址

https://leetcode.com/problems/max-consecutive-ones-iii/

题目描述

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 <= A.length <= 20000
0 <= K <= A.length
A[i] is 0 or 1

代码

Approach #1 Sliding Window

class Solution {
  public int longestOnes(int[] A, int K) {
        int l = 0;
    int zeros = 0;
    int ans = 0;
    for (int r = 0; r < A.length; r++) {
      if (A[r] == 0) {
        zeros++;
      }
      while (zeros > K) {
        if (A[l++] == 0) {
          zeros--;
        }
      }
      ans = Math.max(ans, r - l + 1);
    }
    return ans;
  }
}

#2

class Solution {
  public int longestOnes(int[] A, int K) {
        int left = 0; 
    int right;
    for (right = 0; right < A.length; right++) {
      if (A[right] == 0) {
        K--;
      }

      if (K < 0) {
        if (A[left] == 0) {
          K++;
        }
        left++;
      }
    }

    return right - left;
  }
}