Minimum Array End

Can you solve this real interview question? Minimum Array End - You are given two integers n and x. You have to construct an array of positive integers nums of size n where for every 0 <= i < n - 1, nums[i + 1] is greater than nums[i], and the result of the bitwise AND operation between all elements of nums is x.

Return the minimum possible value of nums[n - 1].

 

Example 1:

Input: n = 3, x = 4

Output: 6

Explanation:

nums can be [4,5,6] and its last element is 6.

Example 2:

Input: n = 2, x = 7

Output: 15

Explanation:

nums can be [7,15] and its last element is 15.

Solution

class Solution:
    def minEnd(self, n: int, x: int) -> int:
        result = x
        remaining = n - 1
        position = 1
    
        while remaining:
            if not (x & position):
                result |= (remaining & 1) * position
                remaining >>= 1
            position <<= 1
    
        return result