<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 index, vector<set<int>> &graph, vector<bool> &visited, vector<int> &component) {
    cin.tie(nullptr); cout.tie(nullptr); ios_base::sync_with_stdio(false);
    visited[index] = true;
    component.push_back(index); 

  
    for (int neighbor : graph[index]) {
        if (!visited[neighbor]) {
            dfs(neighbor, graph, visited, component);
        }
    }
}

string smallestStringWithSwaps(string s, vector<vector<int>>& pairs) {
    cin.tie(nullptr); cout.tie(nullptr); ios_base::sync_with_stdio(false);
    int n = s.size();
    vector<set<int>> graph(n);


    for (const auto& pair : pairs) {
        graph[pair[0]].insert(pair[1]);
        graph[pair[1]].insert(pair[0]);
    }
    
    vector<bool> visited(n, false);

  
    for (int i = 0; i < n; ++i) {
        if (!visited[i]) {
            vector<int> component;
            dfs(i, graph, visited, component);

           
            vector<char> chars;
            for (int i : component) chars.push_back(s[i]);
                
            
            
            sort(component.begin(), component.end());  
            sort(chars.begin(), chars.end());  
            
            
            for (int j = 0; j < component.size(); ++j) s[component[j]] = chars[j];
                
            
        }
    }

    return s;
}
};
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