2419. Longest Subarray With Maximum Bitwise AND

Medium
You are given an integer array nums of size n.
Consider a non-empty subarray from nums that has the maximum possible bitwise AND.
  • In other words, let k be the maximum value of the bitwise AND of any subarray of nums. Then, only subarrays with a bitwise AND equal to k should be considered.
Return the length of the longest such subarray.
The bitwise AND of an array is the bitwise AND of all the numbers in it.
A subarray is a contiguous sequence of elements within an array.
Example 1:
Input: nums = [1,2,3,3,2,2]
Output: 2
Explanation:
The maximum possible bitwise AND of a subarray is 3.
The longest subarray with that value is [3,3], so we return 2.
Example 2:
Input: nums = [1,2,3,4]
Output: 1
Explanation:
The maximum possible bitwise AND of a subarray is 4.
The longest subarray with that value is [4], so we return 1.
Constraints:
  • 1 <= nums.length <= 10^5
  • 1 <= nums[i] <= 10^6

解題

最大的數字和自己以外的數字做AND就會變小,所以答案其實就是陣列內最大的值它的最大subarray。
Runtime: 124 ms, faster than 100%
Memory Usage: 9.6 MB, less than 33.33%
func longestSubarray(nums []int) int {
maxv := math.MinInt32
count := 0
ans := 0
​
for _, v := range nums {
if v > maxv { maxv = v }
}
​
for _, v := range nums {
if v == maxv {
count++
if count > ans { ans = count }
} else {
count = 0
}
}
​
return ans
}
​