Finding all combinations of well-formed brackets

Question

This came up while talking to a friend and I thought I\'d ask here since it\'s an interesting problem and would like to see other people\'s solutions.

The task is to

Answer 1

Provider C# version based on recursive backtracking algorithm, hope it's helpful.

public List generateParenthesis(int n) {
   List result = new LinkedList();
   Generate("", 0, 0, n, result);
   return result;
}

private void Generate(String s, int l, int r, int n, List result){
   if(l == n && r == n){
       result.add(s);
       return;
   }

   if(l