1493. Longest Subarray of 1s After Deleting One Element

Problem Statement

1493. Longest Subarray of 1's After Deleting One Element

Medium

Given a binary array nums, you should delete one element from it.

Return the size of the longest non-empty subarray containing only 1's in the resulting array. Return 0 if there is no such subarray.

Example 1:

Input: nums = [1,1,0,1]
Output: 3
Explanation: After deleting the number in position 2, [1,1,1] contains 3 numbers with value of 1's.

Example 2:

Input: nums = [0,1,1,1,0,1,1,0,1]
Output: 5
Explanation: After deleting the number in position 4, [0,1,1,1,1,1,0,1] longest subarray with value of 1's is [1,1,1,1,1].

Example 3:

Input: nums = [1,1,1]
Output: 2
Explanation: You must delete one element.

Constraints:

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

Java

Source file

class Solution {
    public int longestSubarray(int[] nums) {
        int penUltStreak = 0, ultStreak = 0, ans = 0;
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] == 1)
                ultStreak++;
            else {
                ans = Math.max(ans, ultStreak + penUltStreak);
                penUltStreak = ultStreak;
                ultStreak = 0;
            }
        }
        ans = Math.max(ans, ultStreak + penUltStreak);
        return Math.min(ans, nums.length - 1); // edge case: if all 1s, atleast one elem must be deleted
    }
}