Max Consecutive Ones

LeetCode: Max Consecutive Ones

Problem

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

Solution

Track a running count of consecutive 1s, resetting it on every 0, and keep the maximum seen so far.

func findMaxConsecutiveOnes(nums []int) int {
    maxOnes := 0
    tempOnes := 0

    for i := 0; i < len(nums); i++ {
        if nums[i] == 1 {
            tempOnes++
        } else {
            tempOnes = 0
        }
        if tempOnes > maxOnes {
            maxOnes = tempOnes
        }
    }

    return maxOnes
}

Complexity

• Time: O(n) — single pass over the array.
• Space: O(1) — only two counters.