<p>You are given an array <code>nums</code> consisting of non-negative integers. You are also given a <code>queries</code> array, where <code>queries[i] = [x<sub>i</sub>, m<sub>i</sub>]</code>.</p>

<p>The answer to the <code>i<sup>th</sup></code> query is the maximum bitwise <code>XOR</code> value of <code>x<sub>i</sub></code> and any element of <code>nums</code> that does not exceed <code>m<sub>i</sub></code>. In other words, the answer is <code>max(nums[j] XOR x<sub>i</sub>)</code> for all <code>j</code> such that <code>nums[j] &lt;= m<sub>i</sub></code>. If all elements in <code>nums</code> are larger than <code>m<sub>i</sub></code>, then the answer is <code>-1</code>.</p>

<p>Return <em>an integer array </em><code>answer</code><em> where </em><code>answer.length == queries.length</code><em> and </em><code>answer[i]</code><em> is the answer to the </em><code>i<sup>th</sup></code><em> query.</em></p>

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

<pre>
<strong>Input:</strong> nums = [0,1,2,3,4], queries = [[3,1],[1,3],[5,6]]
<strong>Output:</strong> [3,3,7]
<strong>Explanation:</strong>
1) 0 and 1 are the only two integers not greater than 1. 0 XOR 3 = 3 and 1 XOR 3 = 2. The larger of the two is 3.
2) 1 XOR 2 = 3.
3) 5 XOR 2 = 7.
</pre>

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

<pre>
<strong>Input:</strong> nums = [5,2,4,6,6,3], queries = [[12,4],[8,1],[6,3]]
<strong>Output:</strong> [15,-1,5]
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length, queries.length &lt;= 10<sup>5</sup></code></li>
	<li><code>queries[i].length == 2</code></li>
	<li><code>0 &lt;= nums[j], x<sub>i</sub>, m<sub>i</sub> &lt;= 10<sup>9</sup></code></li>
</ul>

class Tri{
    public:
    Tri* child[2];
    bool end;
    Tri(){
        end=false;
        child[0]=NULL;
        child[1]=NULL;
    }
};
class Trie{
    public:
    Tri* root;
    Trie(){
        root=new Tri();
    }
    void insert(vector<int>& vc){
        Tri* cr=root;
        for(int x=0;x<32;x++){
            int a=vc[x];
            if(cr->child[a]==NULL){
                Tri* tr=new Tri();
                cr->child[a]=tr;
            }
             cr=cr->child[a];
        }
        cr->end=true;
    }
};
class Solution {
public:
    static bool custom(vector<int>& a,vector<int>& b){
        return a[1]<b[1];
    }
    vector<int> maximizeXor(vector<int>& nums, vector<vector<int>>& queries) {
        sort(nums.begin(),nums.end());
        for(int x=0;x<queries.size();x++){
            queries[x].push_back(x);
        }
        sort(queries.begin(),queries.end(),custom);
        vector<int> ans(queries.size());
        Trie* tr=new Trie();
        int i=0;
        for(int x=0;x<queries.size();x++){
            int lm=queries[x][1];
            int ind=queries[x][2];
            while(i<nums.size() && nums[i]<=lm){
                int nm=nums[i];
                vector<int>v(32);
                for(int y=31;y>=0;y--){
                    int a=(nm%2);
                    nm/=2;
                    v[y]=a;
                }
                tr->insert(v);
                i++;
            }
            int nm=queries[x][0];
            vector<int>v(32);
            for(int y=31;y>=0;y--){
                int a=(nm%2);
                nm/=2;
                v[y]=a;
            }
            Tri* cr=tr->root;
            bool gr=true;
            for(int y=0;y<32;y++){
                int a=v[y];
                int op=1-a;
                if(cr->child[op]==NULL && cr->child[a]==NULL){
                    gr=false;
                    break;
                }
                if(cr->child[op]!=NULL){
                    v[y]=1;
                    cr=cr->child[op];
                }else{
                    v[y]=0;
                    cr=cr->child[a];
                }
            }
            if(!gr){
                ans[ind]=-1;
                continue;
            }
            int as=0;
            for(int y=0;y<32;y++){
                as=2*as+v[y];
            }
            ans[ind]=as;
            
        }
        return ans;
        
    }
};
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