Leetcode 3125. Maximum Number That Makes Result of Bitwise AND Zero

Given an array of nonnegative integers and an upper bound, find the largest integer k (within the allowed range) such that k & num == 0 for every array element — i.e., choose bit positions that are zero in all numbers to maximize k under the constraint. This is a bitmask/greedy problem about identifying free bit positions and constructing the maximum valid bitset.