<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:
    def __init__(self):
        self.N = 10**5 + 1
        self.adj = [[] for _ in range(self.N)]
        self.visited = [False] * self.N
    
    def DFS(self, s, i, chars, indices):
        chars.append(s[i])
        indices.append(i)
        self.visited[i] = True
        
        for neighbour in self.adj[i]:
            if not self.visited[neighbour]:
                self.DFS(s, neighbour, chars, indices)
    
    def smallestStringWithSwaps(self, s, pairs):
        # Build the adjacency list
        for src, dst in pairs:
            self.adj[src].append(dst)
            self.adj[dst].append(src)
        
        s = list(s)  # Convert string to list for mutability
        
        for i in range(len(s)):
            if not self.visited[i]:
                chars = []
                indices = []
                
                # Perform DFS to find connected components
                self.DFS(s, i, chars, indices)
                
                # Sort characters and their indices
                chars.sort()
                indices.sort()
                
                # Place sorted characters back into the string
                for j in range(len(chars)):
                    s[indices[j]] = chars[j]
        
        return ''.join(s)

699