[Java] Array — Max Consecutive Ones

SP Hou
1 min readJul 23, 2020


Given a binary array, find the maximum number of consecutive 1s in this array.

Example 1:

Input: [1,1,0,1,1,1]
Output: 3
Explanation: The first two digits or the last three digits are consecutive 1s.
The maximum number of consecutive 1s is 3.


  • The input array will only contain 0 and 1.
  • The length of input array is a positive integer and will not exceed 10,000

There is a lot going on last month. I need to stop brush code at Leetcode. Maybe I can try to spend few time to resolve Easy problem at Leecode.
This problem is Easy level about Array. But because this problem is “EASY”, so I care the performance. First time, I used while loop, but the performance is very terrible…. so, I try for loop. It’s better than while loop, let alone use Indexof, BinarySearch