<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{
public:
    struct Trie{
        Trie* next[2] = {NULL};
        bool isEnd = false;
    };

    Trie* root;

    TrieNode(){
        root = new Trie();
    }

    void insert(string word){
        Trie* temp = root;

        for(auto &c : word){
            int i = c - '0';
            
            if(!temp->next[i]){
                temp->next[i] = new Trie();
            }

            temp = temp->next[i];
        }

        temp->isEnd = true;
    }

    int calcXor(string word){
        string curr="";

        Trie* temp = root;

        for(auto &c : word){
            int i = c-'0';

            // if(temp->next[1-i]) curr.push_back('1');
            // else curr.push_back('0');
            //temp = temp->next[i];

            if (temp->next[1 - i]) {  // Try to move to the opposite bit
                curr.push_back('1');
                temp = temp->next[1 - i];
            } else {  // Move to the current bit
                curr.push_back('0');
                temp = temp->next[i];
            }
        }

        return stoi(curr, nullptr, 2);
    }
};

class Solution {
public:
    int findMaximumXOR(vector<int>& nums) {
        TrieNode* root = new TrieNode();

        for(auto &it : nums){
            bitset<32> binary(it);
            root->insert(binary.to_string());
        }

        int res=0;

        for(auto &it : nums){
            bitset<32> binary(it);
            int curr = root->calcXor(binary.to_string());

            res = max(res,curr);
        }

        return res;
    }
};
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