Maximum XOR of Two Numbers in an Array LeetCode solution in Python

1
class Solution:
2
    def findMaximumXOR(self, nums: List[int]) -> int:
3
        TrieNode = lambda: defaultdict(TrieNode)
4
        root = TrieNode()
5
        for n in nums:
6
            cur = root
7
            for i in range(31, -1, -1):
8
                bit = 1 if n & (1 << i) else 0
9
                cur = cur[bit]
10
            cur["val"] = n
11

12
        ans = 0
13
        for n in nums:
14
            cur = root
15
            for i in range(31, -1, -1):
16
                bit = 1 if n & (1 << i) else 0
17
                if bit == 1:
18
                    if 0 in cur:
19
                        cur = cur[0]
20
                    else:
21
                        cur = cur[1]
22
                else:
23
                    if 1 in cur:
24
                        cur = cur[1]
25
                    else:
26
                        cur = cur[0]
27
            ans = max(ans, cur["val"] ^ n)
28

29
        return ans