<p>You are given an array of strings <code>equations</code> that represent relationships between variables where each string <code>equations[i]</code> is of length <code>4</code> and takes one of two different forms: <code>&quot;x<sub>i</sub>==y<sub>i</sub>&quot;</code> or <code>&quot;x<sub>i</sub>!=y<sub>i</sub>&quot;</code>.Here, <code>x<sub>i</sub></code> and <code>y<sub>i</sub></code> are lowercase letters (not necessarily different) that represent one-letter variable names.</p>

<p>Return <code>true</code><em> if it is possible to assign integers to variable names so as to satisfy all the given equations, or </em><code>false</code><em> otherwise</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> equations = [&quot;a==b&quot;,&quot;b!=a&quot;]
<strong>Output:</strong> false
<strong>Explanation:</strong> If we assign say, a = 1 and b = 1, then the first equation is satisfied, but not the second.
There is no way to assign the variables to satisfy both equations.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> equations = [&quot;b==a&quot;,&quot;a==b&quot;]
<strong>Output:</strong> true
<strong>Explanation:</strong> We could assign a = 1 and b = 1 to satisfy both equations.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= equations.length &lt;= 500</code></li>
	<li><code>equations[i].length == 4</code></li>
	<li><code>equations[i][0]</code> is a lowercase letter.</li>
	<li><code>equations[i][1]</code> is either <code>&#39;=&#39;</code> or <code>&#39;!&#39;</code>.</li>
	<li><code>equations[i][2]</code> is <code>&#39;=&#39;</code>.</li>
	<li><code>equations[i][3]</code> is a lowercase letter.</li>
</ul>

class Solution {
    
public:
    vector<int> m;
    void dfs(int i,vector<vector<int>> v,vector<bool> &vis,int p){
        vis[i]=true;
        m[i]=p;
      for(int j=0;j<v[i].size();j++){
       if(!vis[v[i][j]]) dfs(v[i][j],v,vis,p);
      }
    }
    bool equationsPossible(vector<string>& equations) {
        m.clear();
        for(int i=0;i<26;i++) m.push_back(0);
        int n=equations.size();
        int k=1;
        vector<vector<int>> v(26);
        for(int i=0;i<n;i++){
           if(equations[i][1]=='='&&(equations[i][0]!=equations[i][3])){
            v[equations[i][0]-'a'].push_back(equations[i][3]-'a');
            v[equations[i][3]-'a'].push_back(equations[i][0]-'a');
           }
        }
        cout<<v['u'-'a'].size();
        vector<bool> vis(26,false);
        for(int i=0;i<26;i++){
            //cout<<i;
            if(!vis[i]&&(v[i].size()!=0)){
                dfs(i,v,vis,k);
                k++;
            }
        }
        //cout<<m[0]<<" "<<m[1];
        for(int i=0;i<n;i++){
            if(equations[i][1]=='!'){
            //cout<<m['a']<<endl;
            if(equations[i][0]==equations[i][3]) return false;
            if(m[equations[i][0]-'a']!=0&&(m[equations[i][0]-'a']==m[equations[i][3]-'a'])) return false;
            }
        }
        return true;
    }
};
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