<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 DSU
{

public:
    vector<int> parent;
    vector<int> rank;

    DSU(int n)
    {
        parent.resize(n, 0);
        rank.resize(n, 0);
        for (int i = 0; i < n; i++)
            parent[i] = i;
    }
    int find(int i)
    {
        if (i == parent[i])
            return i;
        return parent[i] = find(parent[i]);
    }
    void Union(int x, int y)
    {
        int x_parent = find(x);
        int y_parent = find(y);
        if (x_parent == y_parent)
            return;
        if (rank[x_parent] > rank[y_parent])
            parent[y_parent] = x_parent;
        else if (rank[y_parent] > rank[x_parent])
            parent[x_parent] = y_parent;
        else
        {
            parent[x_parent] = y_parent;
            rank[y_parent]++;
        }
    }
};


class Solution {
public:
    int numSimilarGroups(vector<string>& strs) {
        int n=strs.size();
        DSU dsu(n);
        unordered_map<string,int> mp;
        for(int i=0;i<n;i++){
            mp[strs[i]]=i;
        }
        for(int i=0;i<n;i++){
            for(int j=i+1;j<n;j++){
                string a=strs[i],b=strs[j];
                int x=dsu.find(i);
                int y=dsu.find(j);
                int cnt=0;
                for(int k=0;k<a.size();k++){
                    if(a[k]!=b[k]) cnt++;
                    if(cnt>2) break;
                }
                if(cnt<=2) dsu.Union(x,y);
            }
        }
        int ans=0;
        for(int i=0;i<n;i++){
            if(dsu.parent[i]==i) ans++;
        }
        return ans;
    }
};
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