<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 dfs(int src,vector<vector<int>> &adjList,vector<int> &curr,vector<int> &vis){
        if(vis[src]) {
            return;
        }
        curr.push_back(src);
        vis[src]=true;
        for(auto& node:adjList[src]){
            dfs(node,adjList,curr,vis);
        }
    }
public:
    string smallestStringWithSwaps(string s, vector<vector<int>>& pairs) {
        vector<int> vis(s.size(),0);
        vector<vector<int>> adjList(s.size());
        vector<vector<int>>  v;
        for(auto& p:pairs){
            adjList[p[0]].push_back(p[1]);
            adjList[p[1]].push_back(p[0]);
        }
        for(int i=0;i<s.size();i++){
            if(!vis[i]){
                vector<int> curr;
                dfs(i,adjList,curr,vis);
                v.push_back(curr);
            }
        }
        for(auto& nums:v){
            sort(nums.begin(),nums.end());
            string curr="";
            for(int num:nums) curr+=s[num];
            sort(curr.begin(),curr.end());
            for(int i=0;i<nums.size();i++) s[nums[i]]=curr[i];
        }
        return s;
    }
};
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