<p>You are given a string <code>s</code>, and an array of pairs of indices in the string&nbsp;<code>pairs</code>&nbsp;where&nbsp;<code>pairs[i] =&nbsp;[a, b]</code>&nbsp;indicates 2 indices(0-indexed) of the string.</p>

<p>You can&nbsp;swap the characters at any pair of indices in the given&nbsp;<code>pairs</code>&nbsp;<strong>any number of times</strong>.</p>

<p>Return the&nbsp;lexicographically smallest string that <code>s</code>&nbsp;can be changed to after using the swaps.</p>

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

<pre>
<strong>Input:</strong> s = &quot;dcab&quot;, pairs = [[0,3],[1,2]]
<strong>Output:</strong> &quot;bacd&quot;
<strong>Explaination:</strong> 
Swap s[0] and s[3], s = &quot;bcad&quot;
Swap s[1] and s[2], s = &quot;bacd&quot;
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;dcab&quot;, pairs = [[0,3],[1,2],[0,2]]
<strong>Output:</strong> &quot;abcd&quot;
<strong>Explaination: </strong>
Swap s[0] and s[3], s = &quot;bcad&quot;
Swap s[0] and s[2], s = &quot;acbd&quot;
Swap s[1] and s[2], s = &quot;abcd&quot;</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;cba&quot;, pairs = [[0,1],[1,2]]
<strong>Output:</strong> &quot;abc&quot;
<strong>Explaination: </strong>
Swap s[0] and s[1], s = &quot;bca&quot;
Swap s[1] and s[2], s = &quot;bac&quot;
Swap s[0] and s[1], s = &quot;abc&quot;
</pre>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 10^5</code></li>
	<li><code>0 &lt;= pairs.length &lt;= 10^5</code></li>
	<li><code>0 &lt;= pairs[i][0], pairs[i][1] &lt;&nbsp;s.length</code></li>
	<li><code>s</code>&nbsp;only contains lower case English letters.</li>
</ul>

class Solution {
public:
    int find(int x,vector<int> &parent){
        if(parent[x]==-1){
            return x;
        }
        return parent[x]=find(parent[x],parent);
    }

    void uni(int u,int v,vector<int> &rank,vector<int> &parent){
        int p1=find(u,parent);
        int p2=find(v,parent);

        if(p1!=p2){
            if(rank[p1]>rank[p2]){
                parent[p2]=p1;
            }
            else if(rank[p1]<rank[p2]){
                parent[p1]=p2;
            }
            else{
                parent[p2]=p1;
                rank[p1]++;
            }
        }
    }
    string smallestStringWithSwaps(string s, vector<vector<int>>& pairs) {
        int n=s.size();

        vector<int> parent(n,-1);
        vector<int> rank(n,1);

        for(int i=0;i<pairs.size();i++){
            int u=pairs[i][0];
            int v=pairs[i][1];

            uni(u,v,rank,parent);
        }

        vector<pair<char,int>> v;
        for(int i=0;i<n;i++){
            v.push_back({s[i],i});
        }

        vector<vector<int>> comp(n);

        sort(v.begin(),v.end());

        for(int i=0;i<n;i++){
            int p=find(v[i].second,parent);
            comp[p].push_back(v[i].second);
        }

        vector<int> pos(n);

        string ans(n,'0');

        for(int i=0;i<n;i++){
            int p=find(i,parent);
            int ind=comp[p][pos[p]];
            ans[i]=s[ind];
            pos[p]++;
        }

        // for(int i=0;i<n;i++){
        //     cout<<i<<"->";
        //     for(int j=0;j<comp[i].size();j++){
        //         cout<<comp[i][j]<<" ";
        //     }
        //     cout<<endl;
        // }

        return ans;
    }
};
56337