<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 smallestStringWithSwaps(self, s: str, pairs: List[List[int]]) -> str:
        graph = collections.defaultdict(set)
        for p in pairs:
            a, b = p[0], p[1]

            graph[a].add(b)
            graph[b].add(a)
        
        parents = [i for i in range(len(s))]
        ranks = [1] * len(s)

        def get_parent(i):
            parent = parents[i]
            while parents[parent] != parent:
                parents[parent] = parents[parents[parent]]
                parent = parents[parent]
            return parent
        
        def union(i,j):
            parent_i = get_parent(i)
            parent_j = get_parent(j)

            if ranks[i] >= ranks[j]:
                ranks[j] += ranks[i]
                parents[parent_i] = parents[parent_j]
            else:
                ranks[i] += ranks[j]
                parents[parent_j] = parents[parent_i]
            

        for p in pairs:
            union(p[0], p[1])
        
        sets = {}#collections.defaultdict(collections.deque())
        for i in range(len(s)):
            key = get_parent(i)
            if key not in sets:
                sets[key] = []
            sets[key].append(s[i])
        
        for i in sets:
            sets[i] = collections.deque(sorted(sets[i]))
        
        res = []
        for i in range(len(s)):
            set_curr = sets[get_parent(i)]
            next_char = set_curr.popleft()
            res.append(next_char)
        
        return "".join(res)
575