<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:
//     vector<int> par,size;
//     int find(int a){
//         if(par[a]==a)
//         return a;
//         return par[a]=find(par[a]);
//     }
//     void unon(int i, int j){
//         int par_i=find(i);
//         int par_j=find(j);

//         if(par_i!=par_j){
//             if(size[par_i]>size[par_j]){
//                 par[par_j]=par[par_i];
//                 size[par_i]+=size[par_j];
//             }
//             else{
//                 par[par_i]=par[par_j];
//                 size[par_j]+=size[par_i];
//             }
//         }
//     }
//     bool is_con(string &a, string &b){
//         int n=a.size();
//         int count=0;
//         vector<int> diff(2);
//         for(int i=0;i<n;i++){
//             if(a[i]!=b[i]){
//                 count++;
//                 if(count>=3)
//                 return false;
//                 diff.push_back(i);
//             }
            
//         }
//         if(count==0)
//         return true;
//         if(count==2&&(a[diff[0]]==b[diff[1]]&&a[diff[1]]==b[diff[0]]))
//         return true;
//         return false;
//     }
//     int numSimilarGroups(vector<string>& strs) {
//         int n=strs.size();
//         size.assign(n,1);
//         par.assign(n,1);
//         for(int i=0;i<n;i++){
//             par[i]=i;
//         }
//         for(int i=0;i<n;i++){
//             for(int j=0;j<n;j++){
//                 if(is_con(strs[i],strs[j])){
//                     unon(i,j);
//                 }
//             }
//         }

//         unordered_set<int> st;
//         for(int i=0;i<n;i++){
//             st.insert(find(i));
//         }
//         return st.size();




//     }
// };

#include <vector>
#include <string>
#include <unordered_set>
using namespace std;

class Solution {
public:
    vector<int> par, size;

    int find(int a) {
        if (par[a] != a) {
            par[a] = find(par[a]);
        }
        return par[a];
    }

    void unionSets(int i, int j) {
        int par_i = find(i);
        int par_j = find(j);

        if (par_i != par_j) {
            if (size[par_i] > size[par_j]) {
                par[par_j] = par_i;
                size[par_i] += size[par_j];
            } else {
                par[par_i] = par_j;
                size[par_j] += size[par_i];
            }
        }
    }

    bool is_con(const string& a, const string& b) {
        int n = a.size();
        int count = 0;
        vector<int> diff;
        for (int i = 0; i < n; i++) {
            if (a[i] != b[i]) {
                count++;
                if (count > 2) return false;
                diff.push_back(i);
            }
        }
        if (count == 0) return true;
        if (count == 2 && a[diff[0]] == b[diff[1]] && a[diff[1]] == b[diff[0]])
            return true;
        return false;
    }

    int numSimilarGroups(vector<string>& strs) {
        int n = strs.size();
        size.assign(n, 1);
        par.resize(n);

        // Initialize the parent array
        for (int i = 0; i < n; i++) {
            par[i] = i;
        }

        // Union similar strings
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < n; j++) {
                if (is_con(strs[i], strs[j])) {
                    unionSets(i, j);
                }
            }
        }

        // Count unique parent representatives
        unordered_set<int> st;
        for (int i = 0; i < n; i++) {
            st.insert(find(i));
        }
        return st.size();
    }
};

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