表达式长度小于255,左圆括号少于20个 importjava.util.Scanner;importjava.util.Stack;publicclassMain{publicstaticvoidmain(String[] args){// TODO Auto-generated method stubScanner in=newScanner(System.in); String s=in.next();intcount=0;//计左括号的个数,初始化0for(inti=0;i<s.length();i++)...