<p>Two strings, <code>X</code> and <code>Y</code>, are considered similar if either they are identical or we can make them equivalent by swapping at most two letters (in distinct positions) within the string <code>X</code>.</p>

<p>For example, <code>&quot;tars&quot;</code>&nbsp;and <code>&quot;rats&quot;</code>&nbsp;are similar (swapping at positions <code>0</code> and <code>2</code>), and <code>&quot;rats&quot;</code> and <code>&quot;arts&quot;</code> are similar, but <code>&quot;star&quot;</code> is not similar to <code>&quot;tars&quot;</code>, <code>&quot;rats&quot;</code>, or <code>&quot;arts&quot;</code>.</p>

<p>Together, these form two connected groups by similarity: <code>{&quot;tars&quot;, &quot;rats&quot;, &quot;arts&quot;}</code> and <code>{&quot;star&quot;}</code>.&nbsp; Notice that <code>&quot;tars&quot;</code> and <code>&quot;arts&quot;</code> are in the same group even though they are not similar.&nbsp; Formally, each group is such that a word is in the group if and only if it is similar to at least one other word in the group.</p>

<p>We are given a list <code>strs</code> of strings where every string in <code>strs</code> is an anagram of every other string in <code>strs</code>. How many groups are there?</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> strs = [&quot;tars&quot;,&quot;rats&quot;,&quot;arts&quot;,&quot;star&quot;]
<strong>Output:</strong> 2
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> strs = [&quot;omv&quot;,&quot;ovm&quot;]
<strong>Output:</strong> 1
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= strs.length &lt;= 300</code></li>
	<li><code>1 &lt;= strs[i].length &lt;= 300</code></li>
	<li><code>strs[i]</code> consists of lowercase letters only.</li>
	<li>All words in <code>strs</code> have the same length and are anagrams of each other.</li>
</ul>

class Solution {
public:
    int numSimilarGroups(vector<string>& strs) {
        
        vector<vector<int>> edges;
        vector<int> par;

        for(int i=0;i<strs.size();i++)
        {
            for(int j=i+1;j<strs.size();j++)
            {
                if(check(strs[i],strs[j]))
                    edges.push_back({i,j});
            }
            par.push_back(i);
        }
        
        for(auto a: edges)
        {
            
            int para=findPar(par,a[0]);
            int parb=findPar(par,a[1]);
            
            if(para!=parb)
            {
                par[parb]=para;
            }
        }
        
        unordered_set<int> ss;
        for(int i=0;i<par.size();i++)
        {
            int t=findPar(par,i);
            ss.insert(par[i]);
        }
        
        return ss.size();
    }
    
    int findPar(vector<int> &par, int curr)
    {
        if(curr==par[curr])
            return curr;
        return par[curr]=findPar(par,par[curr]);
    }
    
    bool check(string &a, string &b)
    {
        vector<vector<int>> misplaced;
        
        if(a.size()!=b.size())
            return false;
        
        for(int i=0;i<a.size();i++)
        {
            if(a[i]!=b[i])
            misplaced.push_back({a[i],b[i]});
            
            if(misplaced.size()>2)
                return false;
        }
        
        if(misplaced.empty())
            return true;
        
        if(misplaced.size() == 2  && misplaced[0][1]==misplaced[1][0] && misplaced[1][0]==misplaced[0][1])
            return true;
        
        return false;
    }
};

139048