Allpermutationofparanthesis.java

import java.io.*;

class Allpermutationofparanthesis {
    static void _printParenthesis(char str[], int pos,
            int n, int open,
            int close) {
        if (close == n) {
            for (int i = 0; i < str.length; i++)
                System.out.print(str[i]);
            System.out.println();
            return;
        } else {
            if (open > close) {
                str[pos] = '}';
                _printParenthesis(str, pos + 1, n, open,
                        close + 1);
            }
            if (open < n) {
                str[pos] = '{';
                _printParenthesis(str, pos + 1, n, open + 1,
                        close);
            }
        }
    }

    static void printParenthesis(char str[], int n) {
        if (n > 0)
            _printParenthesis(str, 0, n, 0, 0);
        return;
    }

    public static void main(String[] args) {
        int n = 3;
        char[] str = new char[2 * n];
        printParenthesis(str, n);
    }
}