24分就很离谱 java

import java.util.LinkedList;
import java.util.Scanner;
import java.util.Stack;

public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        LinkedList<String> list = new LinkedList();
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        for (int i = 0; i < s.length(); i++) {
            list.add(i, s.substring(i,i+1));
        }
        for (int i = 0; i < s.length(); i++) {
            String c = list.get(i);
            switch(c) {
            case "(":
                for (int j = i+1; j < s.length(); j++) {
                    if(list.get(i)==")") {
                        System.out.print(c+j);
                        break;
                    }
                }
                System.out.print(c+")");
                break;

            case "[":

                for (int j = i+1; j < s.length(); j++) {
                    if(list.get(i)=="]") {
                        System.out.print(c+j);
                        break;
                    }
                }
                System.out.print(c+"]");
                break;

            }
        }

    }

}