<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 genPar(int n,string temp,vector<string>& ans,int index,int oc,int cc){
        //BC
        if(index == 2*n){
            if(oc==cc){
                ans.push_back(temp);
            }
            return;
        }

        temp.push_back('(');
        oc++;
        genPar(n,temp,ans,index+1,oc,cc);
        temp.pop_back();
        oc--;
        temp.push_back(')');
        cc++;
        if(cc>oc) return;
        genPar(n,temp,ans,index+1,oc,cc);
    }
    vector<string> generateParenthesis(int n) {
         int index = 1;
        string temp ="(";
        int oc = 1;
        int cc = 0;
        vector<string> ans;
        genPar(n,temp,ans,index,oc,cc);
        return ans;
    }
};
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