<p>Given an integer array <code>nums</code>, return <em>the maximum result of </em><code>nums[i] XOR nums[j]</code>, where <code>0 &lt;= i &lt;= j &lt; n</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [3,10,5,25,2,8]
<strong>Output:</strong> 28
<strong>Explanation:</strong> The maximum result is 5 XOR 25 = 28.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [14,70,53,83,49,91,36,80,92,51,66,70]
<strong>Output:</strong> 127
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 2 * 10<sup>5</sup></code></li>
	<li><code>0 &lt;= nums[i] &lt;= 2<sup>31</sup> - 1</code></li>
</ul>

class TrieNode:
    def __init__(self, val: int) -> None:
        self.val = val
        self.childrens = [None, None]

class Trie:
    def __init__(self) -> None:
        self.root = TrieNode(val = -1)
    
    def add(self, num: int) -> None:
        tmp = self.root
        for i in range(31, -1, -1):
            bit = 1 if ((num & (1<<i)) > 0 ) else 0
            
            if tmp.childrens[bit] == None:
                nn = TrieNode(bit)
                tmp.childrens[bit] = nn
            
            tmp = tmp.childrens[bit]
    
    def maxXor(self, num: int) -> int:
        value = 0
        tmp = self.root

        for i in range(31, -1, -1):
            bit = 1 if ((num & (1<<i)) > 0 ) else 0
            rev_bit = 1 if bit==0 else 0
            #print(f"bit pos: {i}, bit val: {bit}")

            if tmp.childrens[rev_bit] != None:
                #print(f"rev bit found for bit pos: {i}")
                value += (1<<i)
                tmp = tmp.childrens[rev_bit]
            else:
                tmp = tmp.childrens[bit]
        
        return value

from typing import List

class Solution:
    def findMaximumXOR(self, nums: List[int]) -> int:

        tr = Trie()
        for ai in nums:
            tr.add(num= ai)
        
        max_xor = 0
        for ai in nums:
            max_poss_xor = tr.maxXor(num= ai)
            max_xor = max(max_xor, max_poss_xor)
        
        return max_xor
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