<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 {
    void visit(string& s, vector<vector<int>>& adjList, vector<bool>& vis, int ind, string& currAns, vector<int>& currInd)
    {
        vis[ind] = true;
        currAns.push_back(s[ind]);
        currInd.push_back(ind);

        for(int neigh: adjList[ind])
        {
            if(!vis[neigh])
            {
                visit(s, adjList, vis, neigh, currAns, currInd);
            }
        }
    }
public:
    string smallestStringWithSwaps(string s, vector<vector<int>>& pairs) {
        int n = s.length();
        vector<vector<int>> adjList(n);
        for(auto pair: pairs)
        {
            adjList[pair[0]].push_back(pair[1]);
            adjList[pair[1]].push_back(pair[0]);
        }

        string ans(n, ' ');
        vector<bool> vis(n, false);
        for(int i=0;i<n;i++)
        {
            if(!vis[i])
            {
                string currAns = "";
                vector<int> currInd;
                visit(s, adjList, vis, i, currAns, currInd);

                sort(currAns.begin(), currAns.end());
                sort(currInd.begin(), currInd.end());
                for(int i=0;i<currAns.length();i++)
                {
                    ans[currInd[i]]=currAns[i];
                }
            }
        }
        return ans;
    }
};
76812