1004

1004. Max Consecutive Ones III (Medium)

Given a binary array nums and an integer k, return the maximum number of consecutive 1's in the array if you can flip at most k 0's.

 

Example 1:

Input: nums = [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: nums = [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.

 

Constraints:

• 1 <= nums.length <= 105
• nums[i] is either 0 or 1.
• 0 <= k <= nums.length

Companies:
Facebook, DE Shaw, Apple, Amazon, Microsoft, Adobe

Related Topics:
Array, Binary Search, Sliding Window, Prefix Sum

Similar Questions:

• Longest Substring with At Most K Distinct Characters (Medium)
• Longest Repeating Character Replacement (Medium)
• Max Consecutive Ones (Easy)
• Max Consecutive Ones II (Medium)

Solution 1. Sliding Window

Check out "C++ Maximum Sliding Window Cheatsheet Template!"

Shrinkable sliding window:

// OJ: https://leetcode.com/problems/max-consecutive-ones-iii/
// Author: github.com/lzl124631x
// Time: O(N)
// Space: O(1)
class Solution {
public:
    int longestOnes(vector<int>& A, int k) {
        int i = 0, j = 0, cnt = 0, N = A.size(), ans = 0;
        while (j < N) {
            cnt += A[j++] == 0;
            while (cnt > k) cnt -= A[i++] == 0;
            ans = max(ans, j - i);
        }
        return ans;
    }
};

Or non-shrinkable sliding window:

// OJ: https://leetcode.com/problems/max-consecutive-ones-iii/
// Author: github.com/lzl124631x
// Time: O(N)
// Space: O(1)
class Solution {
public:
    int longestOnes(vector<int>& A, int k) {
        int i = 0, j = 0, cnt = 0, N = A.size();
        while (j < N) {
            cnt += A[j++] == 0;
            if (cnt > k) cnt -= A[i++] == 0;
        }
        return j - i;
    }
};

Discuss

https://leetcode.com/problems/max-consecutive-ones-iii/discuss/1504260/C%2B%2B-Sliding-Window-(%2B-Cheat-Sheet)