<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:
        d = self.Dset()
        for pair in pairs:
            pA = d.add(pair[0])
            pB = d.add(pair[1])
            d.join(pA, pB)
        group = []
        for node in d.mp.values():
            if node is d.find(node):
                group.append(node.value)
        pmap = {x: {x} for x in group}  # map from parents to their range of mods
        # print("pmap", pmap.keys())
        for v in d.mp.values():
            root = d.find(v)
            # print("rv",root.value)
            pmap[root.value].add(v.value)
        sol = list(s)
        for modList in pmap.values():
            currList = []
            modList = sorted(modList)
            currList = [s[idx] for idx in modList]
            # for idx in modList:
            #    currList.append(s[idx])
            currList.sort()
            cidx = 0
            for idx in modList:
                sol[idx] = currList[cidx]
                cidx += 1
        return "".join(sol)
    class Dset:
        class Node:
            def __init__(self, value=None):
                self.value = value
                self.parent = self
                self.rank = 1
        def __init__(self):
            self.mp = {}
        def find(self, node):
            trav = node
            while trav is not trav.parent:
                trav = trav.parent
            node.parent = trav
            return trav
        def join(self, nA, nB):
            pA = self.find(nA)
            pB = self.find(nB)
            if pA is pB:
                return

            if pA.rank < pB.rank:
                pB.parent = pA
                # if pB.value in self.parents:
                #     self.parents.remove(pB.value)
            else:
                pA.parent = pB
                # if pA.value in self.parents:
                #     self.parents.remove(pA.value)
                if pA.rank == pB.rank:
                    pB.rank += 1
        def add(self, value):
            if value not in self.mp:
                node = self.Node(value)
                self.mp[value] = node
                return node
            else:
                return self.mp[value]

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