Maximum XOR of Two Numbers - Implementation

Here is the implementation using a trie:

class TrieNode:
    children = [null, null]  // 0 and 1

function findMaximumXOR(nums):
    root = new TrieNode()

    // Insert all numbers
    for num in nums:
        node = root
        for i from 31 down to 0:
            bit = (num >> i) & 1
            if node.children[bit] == null:
                node.children[bit] = new TrieNode()
            node = node.children[bit]

    maxXor = 0
    for num in nums:
        node = root
        currentXor = 0
        for i from 31 down to 0:
            bit = (num >> i) & 1
            oppositeBit = 1 - bit
            if node.children[oppositeBit] != null:
                currentXor |= (1 << i)
                node = node.children[oppositeBit]
            else:
                node = node.children[bit]
        maxXor = max(maxXor, currentXor)

    return maxXor

$O(32n) = O(n)$ time, $O(32n)$ space for trie.