void printBrackets(int n ,string s,int oc ,int cc )
{
if(oc ==n && cc == n){
cout<<s<<"\n";
return;
}
if(oc<n){
s += "(";
printBrackets(n,s,oc +1,cc);
}
if(oc>cc){
s += ")";
printBrackets(n,s,oc,cc+1);
}
}
(())
(()()