题解 | 括号配对问题

import java.util.*;
public class Main{
    public static void main(String[] args){
        Deque<Character> stack = new ArrayDeque<>();
        Scanner in = new Scanner(System.in);
        String s = in.next();
        stack.push('a');//防止')',']'先手,导致误判
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)=='('||s.charAt(i)=='['){
                stack.push(s.charAt(i));
                continue;
            }
            if(s.charAt(i)==')'&&!stack.isEmpty()){
                char c = stack.pop();
                if(c!='('){
                    System.out.println(false);
                    return;
                }
                continue;
            }
            if(s.charAt(i)==']'&&!stack.isEmpty()){
                char c = stack.pop();
                if(c!='['){
                    System.out.println(false);
                    return;
                }
            }
        }
        stack.pop();//清除加入a带来的影响
       if(!stack.isEmpty())
        System.out.println(false);
       else System.out.println(true);
    }
}