<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>

struct Node {
    Node* links[2] = {nullptr};
    
    bool containsKey(char ch) {
        return links[ch - '0'] != nullptr;
    }
    
    void put(char ch, Node* node) {
        links[ch - '0'] = node;
    }
    
    Node* get(char ch) {
        return links[ch - '0'];
    }
};

class Trie {
private:
    Node* root;    
public:
    Trie() {
        root = new Node();
    }
    
    void insert(int n) {
        string binary = bitset<32>(n).to_string();
        Node* node = root;
        for (char ch : binary) {
            if (!node->containsKey(ch)) {
                node->put(ch, new Node());
            }
            node = node->get(ch);
        }
    }
    
    int getMaximum(int n) {
        string binary = bitset<32>(n).to_string();
        Node*node=root;
        unsigned int val=(1<<31);
        int maxi=0;
        for(char ch:binary){
            char oB = (ch == '0') ? '1' : '0'; // opposite Bit
            if (node->containsKey(oB)) {
                maxi+=val;
                node = node->get(oB);
            } else node = node->get(ch);
            val/=2;
        }
        return maxi;
    }
};

class Solution {
public:
    int findMaximumXOR(vector<int>& nums) {
        Trie trie;
        for (int ele : nums) {
            trie.insert(ele);
        }
        
        int maxi = 0;
        for (int ele : nums) {
            maxi = max(maxi, trie.getMaximum(ele));
        }
        
        return maxi;
    }
};
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