nestedParenthesis

#include<string>
#include<iostream>
#include<set>
using namespace std;

void nestedParenthesis(set<string>&paren, int n)
{
	if(n == 1)	{
		paren.insert("()");
		return;
	}
	nestedParenthesis(paren,n-1);
	set<string> tempara;
	for(set<string>::iterator it = paren.begin();it !=paren.end();it++ ){
		string temp = *it;
		tempara.insert("()"+ temp);
		unsigned int i =0;
		while(i<temp.length()){
			if(temp[i] == '('){
				tempara.insert(temp.substr(0,i+1)+"()"+temp.substr(i+1));
			}
			i++;
		}
	}
	//for n=3 , the output is :((())), (() ()), (()) (), () (()), () () ()
	paren.clear();
	//copy tempara to paren
	for(set<string>::iterator it = tempara.begin();it !=tempara.end();it++ ){
		paren.insert(*it);
	}
	
}

int main()
{
	int n= 3;
	set<string> paren;
	nestedParenthesis(paren,n);
	for(set<string>::iterator vit = paren.begin();vit != paren.end();vit++)
		cout<<*vit<<endl;
	return 0;
}