<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 UnionFind:
    def __init__(self, n):
        self.parents = [i for i in range(n)]
        self.ranks = [0 for _ in range(n)]
    def find(self, i):
        if self.parents[i] == i:
            return i
        p = self.find(self.parents[i])
        self.parents[i] = p
        return p
    def union(self, i, j):
        u, v = self.find(i), self.find(j)
        if u == v:
            return
        p, q = self.ranks[u], self.ranks[v]
        if p > q:
            self.parents[v] = u
        elif p < q:
            self.parents[u] = v
        else:
            self.parents[v] = u
            self.ranks[u] += 1


class Solution:
    def get(self, cnts):
        for i in range(26):
            if cnts[i] > 0:
                cnts[i] -= 1
                return i
        return -1
    def smallestStringWithSwaps(self, s: str, pairs: List[List[int]]) -> str:
        n = len(s)
        uf = UnionFind(n)
        for u, v in pairs:
            uf.union(u, v)
        cnts = [[0 for _ in range(26)] for _ in s]
        for i in range(n):
            p = uf.find(i)
            cnts[p][ord(s[i]) - ord('a')] += 1
        ans = [0 for _ in range(n)]
        for i in range(n):
            ans[i] = self.get(cnts[uf.find(i)])
        return ''.join(map(lambda x: chr(ord('a') + x), ans))
654