<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:
    unordered_map<string, string> parents;
    unordered_map<string, int> ranks;
    
    int PARENTS = 0;
    
    void addSet(string &val) {
        if (parents.count(val)) return;
        parents[val] = val;
        ranks[val] = 0;
        PARENTS++;
    }
    
    string findSet(string &val) {
        if (parents[val] == val) {
            return val;
        }
        return parents[val] = findSet(parents[val]);
    }
    
    void unionSet(string val1, string val2) {
        string parent1 = findSet(val1);
        string parent2 = findSet(val2);
        
        if (parent1 == parent2) return;
        
        if (ranks[parent1] > ranks[parent2]) {
            parents[parent2] = parent1;
        } else if (ranks[parent1] < ranks[parent2]) {
            parents[parent1] = parent2;
        } else {
            parents[parent2] = parent1;
            ranks[parent1]++;
            ranks[parent2] = 0;
        }
        PARENTS--;
    }
    
    bool areSimilar(string &s1, string &s2) {
        int diff = 0;
        for (int i = 0; i < s1.size(); i++) {
            if (s1[i] != s2[i]) {
                if (++diff > 2) {
                    return false;
                }
            }
        }
        return true;
    }
    
    void generateCombinations(vector<string> &words) {
        for (auto &w: words) {
            addSet(w);
        }
        for (int i = 0; i < words.size(); i++) {
            for (int j = 0; j < words.size(); j++) {
                if (i != j && areSimilar(words[i], words[j])) {
                    
                    unionSet(words[i], words[j]);
                }
            }
        }
    }
    
    int numSimilarGroups(vector<string>& strs) {
        generateCombinations(strs);
        
        return PARENTS;
        
//         for (auto [child, parent]: parents) {
//             uniqueParents.insert(parent);
//         }
        
//         return uniqueParents.size();
    }
};
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