<p>Given <code>n</code> pairs of parentheses, write a function to <em>generate all combinations of well-formed parentheses</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> n = 3
<strong>Output:</strong> ["((()))","(()())","(())()","()(())","()()()"]
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> n = 1
<strong>Output:</strong> ["()"]
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= n &lt;= 8</code></li>
</ul>

class Solution {
public:
    void fun(int open, int closed, string temp, vector<string>&ans, int n)
    {
      if(open==n&&closed==n){
        ans.push_back(temp);
      } 
      if(open<=n){
        fun(open+1,closed,temp+'(',ans,n);

      } 
      if(open>closed&&closed<=n){
        fun(open,closed+1,temp+')',ans,n);
      }

    }
    vector<string> generateParenthesis(int n) {
        vector<string>ans;
        fun(0,0,"",ans,n);
        return ans;
        
    }
};
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