<p>We want to split a group of <code>n</code> people (labeled from <code>1</code> to <code>n</code>) into two groups of <strong>any size</strong>. Each person may dislike some other people, and they should not go into the same group.</p>

<p>Given the integer <code>n</code> and the array <code>dislikes</code> where <code>dislikes[i] = [a<sub>i</sub>, b<sub>i</sub>]</code> indicates that the person labeled <code>a<sub>i</sub></code> does not like the person labeled <code>b<sub>i</sub></code>, return <code>true</code> <em>if it is possible to split everyone into two groups in this way</em>.</p>

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

<pre>
<strong>Input:</strong> n = 4, dislikes = [[1,2],[1,3],[2,4]]
<strong>Output:</strong> true
<strong>Explanation:</strong> The first group has [1,4], and the second group has [2,3].
</pre>

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

<pre>
<strong>Input:</strong> n = 3, dislikes = [[1,2],[1,3],[2,3]]
<strong>Output:</strong> false
<strong>Explanation:</strong> We need at least 3 groups to divide them. We cannot put them in two groups.
</pre>

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

<ul>
	<li><code>1 &lt;= n &lt;= 2000</code></li>
	<li><code>0 &lt;= dislikes.length &lt;= 10<sup>4</sup></code></li>
	<li><code>dislikes[i].length == 2</code></li>
	<li><code>1 &lt;= a<sub>i</sub> &lt; b<sub>i</sub> &lt;= n</code></li>
	<li>All the pairs of <code>dislikes</code> are <strong>unique</strong>.</li>
</ul>

class Solution {
public:
    bool possibleBipartition(int n, vector<vector<int>>& dislikes) {
        vector<int>color(n+1,-1);
        vector<int> vis(n+1,0);
        map<int,vector<int>> mp;
        for(int i=0;i<dislikes.size();++i)
        {
            mp[dislikes[i][0]].push_back(dislikes[i][1]);
            mp[dislikes[i][1]].push_back(dislikes[i][0]);
        }
        for(int i=1;i<=n;++i)
        {
            if(vis[i]==1)
                continue;
            queue<int>q;
            q.push(i);
            color[i]=0;
            vis[i]=1;
            while(!q.empty())
            {
                auto ele=q.front();
                q.pop();
                for(int i=0;i<mp[ele].size();++i)
                {
                    if(color[mp[ele][i]]==-1 || color[mp[ele][i]]!=color[ele])
                    {
                        if(vis[mp[ele][i]]==0)
                        {
                            vis[mp[ele][i]]=1;
                            color[mp[ele][i]]=1-color[ele];
                            q.push(mp[ele][i]);
                        }
                        
                    }
                    else
                        return false;

                }
        }

        }
       
        return true;

    }
};
71728