<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:
    bool isSimilar(string a,string b){
        int count =0;
        for(int i=0;i<a.size();i++){
            if(a[i] != b[i]){
                count++;
            }
        }

        return count<=2 ? true : false;
    }

    int find(vector<int>&parent, int x){
        if(parent[x] != x){
            parent[x] = find(parent,parent[x]);
        }

        return parent[x];
    }

    void merge(vector<int>&parent,int a,int b,vector<int>& rank){
        if(rank[a] < rank[b]){
            parent[a] = b;
        } else if(rank[b] < rank[a]){
            parent[b] = a;
        } else{
            parent[a] = b;
            rank[b] +=1;
        }
    }

    int numSimilarGroups(vector<string>& strs) {
        int n= strs.size();
        vector<int> parent(strs.size(),0);
        vector<int> rank(strs.size(),0);
        for(int i=0;i<strs.size();i++){
            parent[i] = i;
        }

        for(int i=0;i<strs.size();i++){
            for(int j=0;j<strs.size();j++){
                int parentA = find(parent,i);
                int parentB = find(parent,j);

                if(parentA != parentB && isSimilar(strs[i],strs[j])){
                    merge(parent,parentA,parentB,rank);
                    n--;
                }
            }
        }

        return n;
    }
};
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