<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:

void fun(int i,vector<vector<int>>&v,vector<bool>&vis,vector<int>&res){
  if(vis[i])return ;
   
  vis[i]=1;
  
  res.push_back(i);
 
  for(int k=0;k<v[i].size();k++)
     fun(v[i][k],v,vis,res);

}

void fill(string &str,vector<int> &res,set<pair<int,char>>&s){
   
    string temp="";
    for(int i=0;i<res.size();i++)
      temp.push_back(str[res[i]]);

    sort(temp.begin(),temp.end());
    sort(res.begin(),res.end());
   
   int c=0;
  for(int i=0;i<res.size();i++)
    s.insert({res[i],temp[i]});
    
}

string smallestStringWithSwaps(string str, vector<vector<int>> &pairs){
 vector<vector<int>>v(str.size());
 vector<bool>vis(str.size(),0);
  // map<pair<char,int>,bool>st;
  // map<pair<char,int>,int>idx;
   set<pair<int,char>>s;
  for(int i=0;i<pairs.size();i++){
     v[pairs[i][0]].push_back(pairs[i][1]);
     v[pairs[i][1]].push_back(pairs[i][0]);
  }

  string ans="";
  for(int i=0;i<str.size();i++){
     vector<int>res;
     fun(i,v,vis,res);   
     fill(str,res,s);
  }
  for(auto i:s)
    ans+=i.second;
    
  return ans;
}


};
79962