<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:
    vector<int> rank, par;
    Solution() {
        // Default constructor implementation
    }
    Solution(int n){
        rank = vector<int> (n,1);
        for(int i=0; i<n; i++){
            par.push_back(i);
        }
    }
    int find(int x){
        if(par[x] == x) return x;
        return par[x] = find(par[x]);
    }
    void union_(int x , int y){
        int parx = find(x), pary = find(y);
        if(parx == pary) return;
        if(rank[parx] > rank[pary]){
            par[pary] = parx;
            rank[parx]+=rank[pary];
        }
        else{
            par[parx] = pary;
            rank[pary]+=rank[parx];
        }
        return;
    }
    string smallestStringWithSwaps(string s, vector<vector<int>>& pairs) {
        Solution ds(s.size());
        map<int, priority_queue<char, vector<char>, greater<char>>> mp;
        for(int i=0; i<pairs.size(); i++){
            ds.union_(pairs[i][0], pairs[i][1]);
        }
        for(int i=0; i<s.size(); i++){
            mp[ds.find(i)].push(s[i]);
        }
        for(int i=0; i<s.size(); i++){
            s[i] = mp[ds.find(i)].top();
            mp[ds.find(i)].pop();
        }
        return s;
    }
};
52662