<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 dfs(int idx, vector<int>&nodes ,vector<int>&visited, vector<vector<int>>&adj){
        nodes.push_back(idx);
        visited[idx] = 1;
        for(int it:adj[idx]){
            if(!visited[it]){
                dfs(it, nodes, visited, adj);
            }
        }
    }
    string smallestStringWithSwaps(string s, vector<vector<int>>& pairs) {
        vector<vector<int>>adj(s.size());
        for(int i=0;i<pairs.size();i++){
            adj[pairs[i][0]].push_back(pairs[i][1]);
            adj[pairs[i][1]].push_back(pairs[i][0]);
        }

        vector<int>visited(s.size(), 0);

        vector<vector<int>>components;
        for(int i=0;i<s.size();i++){
            vector<int>v;
            if(!visited[i]){
                dfs(i, v, visited, adj);

            }
            if(!v.empty())components.push_back(v);
        }
        vector<vector<char>>chars(components.size());
        for(int i=0;i<components.size();i++){
            for(int j = 0;j<components[i].size();j++){
                chars[i].push_back(s[components[i][j]]);
            }
            
            
            sort(chars[i].begin(), chars[i].end());
            sort(components[i].begin(), components[i].end());
            for(int k=0;k<components[i].size();k++){
                s[components[i][k]] = chars[i][k];
            }

        }
        return s;


    }
};
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