<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 Disjointset {
    private:
       
    public:
     vector<int> parent, rank, size;
        Disjointset(int n){
            rank.resize(n+1, 0);
            parent.resize(n+1);
            size.resize(n+1, 1);
            for(int i = 0; i<=n; i++){
                parent[i] = i;
            }
        }
        
        int findPar(int node){
            if(parent[node] == node){
                return node;
            }
            return parent[node] = findPar(parent[node]);
        }    
        void unionsize(int u, int v){
            int upa_u = findPar(u);
            int upa_v = findPar(v);
            if(size[upa_u] < size[upa_v]){
                parent[upa_u] = upa_v;
                size[upa_v] += size[upa_u];
            }else{
                parent[upa_v] = upa_u;
                size[upa_u] += size[upa_v];
            }
        }
        
};
class Solution {
public:
    bool val(string a,string b){
        int c=0;
        for(int i=0;i<a.size();i++){
            if(a[i]!=b[i])c++;
        }
        return c<=2;
    }
    int numSimilarGroups(vector<string>& strs) {
        int n=strs.size();
        Disjointset ds(n);
        for(int i=0;i<n;i++){
            string a=strs[i];
            for(int j=i+1;j<n;j++){
                string b=strs[j];
                if(val(a,b)){
                    if(ds.findPar(i)!=ds.findPar(j))ds.unionsize(i,j);
                }
            }
        }
        unordered_set<int>s;
        for(int i=0;i<n;i++){
            int par=ds.findPar(i);
            s.insert(par);
        }
        return s.size();
    }
};
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