生成n对括号的合法全排列

 1 import java.util.Scanner;
 2 import java.util.Stack
 3 public class Main {
 4     public static void main(String []args){
 5         Scanner sc =new Scanner(System.in);
 6         while(sc.hasNext()){
 7             int m =sc.nextInt();
 8             Stack<String> s  =new Stack<String>();
 9             String n ="";
10             generate(m , m, n);
11         }
12     }
13     public static void generate(int leftNum,int rightNum,String s)
14     {
15         if(leftNum==0&&rightNum==0)
16         {
17             System.out.println(s);
18         }
19         if(leftNum>0)
20         {
21             generate(leftNum-1,rightNum,s+‘(‘);
22         }
23         if(rightNum>0&&leftNum<rightNum)
24         {
25             generate(leftNum,rightNum-1,s+‘)‘);
26         }
27     }
28 }