<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:
    string smallestStringWithSwaps(string s, vector<vector<int>>& pairs) {
        
        int n=s.length();
        vector<vector<int>> adjList(n);

        int len=pairs.size();

        for(auto a:pairs)
        {
            adjList[a[0]].push_back(a[1]);
            adjList[a[1]].push_back(a[0]);
        }

        vector<vector<int>> comps;

        vector<bool> visited(n,false);

        for(int i=0;i<n;i++)
        {
            if(!visited[i])
            {
                visited[i]=true;
                queue<int> q;
                q.push(i);  
                vector<int> dup;

                while(q.size()>0)
                {
                    auto top=q.front();
                    q.pop();
                    dup.push_back(top);
                    
                    for(auto a:adjList[top])
                    {
                        if(!visited[a])
                        {
                            visited[a]=true;
                            q.push(a);
                        }
                    }
                }

                sort(dup.begin(),dup.end());
                comps.push_back(dup);
            }
        }

        for(auto a:comps)
        {
            vector<char> dup;

            for(auto b:a)
            {
                dup.push_back(s[b]);
            }
            sort(dup.begin(),dup.end());

            int len=a.size();
            for(int i=0;i<len;i++)
            {
                s[a[i]]=dup[i];
            }
        }
        return s;       
    }
};
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