Is Max Consecutive Ones easy or hard?

Max Consecutive Ones is classified as an Easy problem on LeetCode with an acceptance rate above 60%. The challenge focuses on clean iteration and tracking a running segment length rather than complex algorithms.

How to solve Max Consecutive Ones in O(n)?

Iterate through the binary array while maintaining two variables: current streak and maximum streak. Increment the current streak when the value is 1, otherwise reset it to zero. Update the maximum after each step. This guarantees O(n) time and constant memory usage.

Max Consecutive Ones Python or Java solution?

Python and Java solutions both follow the same logic: iterate through the array, update a running count of consecutive ones, and reset on zeros. The implementation typically fits in a few lines and runs in O(n) time with O(1) space.

What is the best approach for Max Consecutive Ones?

The optimal approach is a single-pass iterative counter. Traverse the array, increase a running counter when you see a 1, and reset it when a 0 appears. Track the maximum streak during the traversal. This runs in O(n) time and O(1) space.

What data structure is used in Max Consecutive Ones?

The problem primarily uses a simple array traversal with integer counters. No additional data structures are required. Some explanations frame the logic using the sliding window technique, but it still operates directly on the array with constant extra space.

What is the time complexity of Max Consecutive Ones?

The standard solution runs in O(n) time because the array is scanned once from left to right. Each element is processed exactly one time. Space complexity remains O(1) since only a few integer counters are maintained.

Is Max Consecutive Ones asked at Google, Amazon, or Meta?

Max Consecutive Ones is a common entry-level array problem and has appeared in interview prep lists associated with companies like Amazon and Google. It is often used to test basic array traversal, state tracking, and understanding of sliding window patterns.

Description Hints 1 Solution Video 3:53

485. Max Consecutive Ones

Easy66.0% acceptance14 companies

Given a binary array nums, return the maximum number of consecutive 1's in the array.

Example 1:

Input: nums = [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.

Example 2:

Input: nums = [1,0,1,1,0,1]
Output: 2

Constraints:

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

Asked at 14 companies

Careem Bloomberg Accenture Cognizant Wipro

Google Amazon Microsoft Meta

Deloitte

TCS

IBM

+2 more

Yandex Apple

Topics

Array

Hints open one at a time

Hint 1

You need to think about two things as far as any window is concerned. One is the starting point for the window. How do you detect that a new window of 1s has started? The next part is detecting the ending point for this window. How do you detect the ending point for an existing window? If you figure these two things out, you will be able to detect the windows of consecutive ones. All that remains afterward is to find the longest such window and return the size.

3:53

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