Today I have done leetcode's November LeetCoding Challenge with cpp.

November LeetCoding Challenge 9

Description

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:

Example 2:

Constraints:

• 1 <= n, x <= 108

Solution

class Solution {
public:
  long long minEnd(int n, int x) {
    long long answer = x;
    long long remain = n - 1;
    long long position = 1;

    while(remain) {
      if(!(x & position)) {
        answer |= (remain & 1) * position;
        remain >>= 1;
      }
      position <<= 1;
    }
    return answer;
  }
};