Leetcode 1707. Maximum XOR With an Element From Array

For each query [x, m], return the maximum value of x XOR nums[j] over all nums[j] ≤ m (or -1 if no such element). The typical efficient approach is to process queries offline by increasing m and maintain a binary XOR trie of eligible nums (values up to ~2^30) to answer each max-XOR query quickly.