▍1. homework
利用栈求表达式的值,可供小学生作业,并能给出分数。(要求:建立试题库文件,随机产生n个题目;题目涉及加减乘除,带括弧的混合运算;随时可以退出;保留历史分数,能回顾历史,给出与历史分数比较后的评价。)(Use of the stack to evaluate the expression, for primary operations, and can give the scores. (Requirements: Create test database files, randomly generating n topics topics involving addition, subtraction, mixed with the parentheses operator ready to quit retain historical scores, can look back at history, given scores compared with the historical evaluation.))