编程介的小学生 2019-07-31 21:51 采纳率: 20.5%
浏览 264

表达式的公式的计算的问题,怎么实现,用C语言

Problem Description
The Advanced Calculator Machinery (ACM) is going to release a new series of calculators. Like it or not, as a member of ACM, you are asked to develop the software for the new calculator. Here is the detailed technical specification.
The general usage of the calculator is that users input expressions, the calculator computes and displays the final result, or error messages if there is something wrong. The expression is in infix notation and the calculator supports following operators:

People always make mistakes. When user inputs an invalid expression, the calculator should display an error message, telling user that error occurs. There are totally four possible errors:
1. Syntax error: Any kind of syntax error, such as missing operators, redundancy operators and unpaired brackets.
2. Divide by zero: The right operand of operator “/” or “%” is zero.
3. Integer overflow: At any step of the calculation, any intermediate values go beyond the range of 32-bit signed integers.
4. Invalid exponent: The right operand of operator“^” is negative, or both operands are zero (we consider 0^0 undefined).
The calculation works this way: at first the calculator omits all space characters of the expression, check the syntax, and then computes. It always finds the highest priority part of the expression, then operators which combines them, then calculate the result and continue the process, until the final result has been got or error occurs.
For example, for expression 2^3^(-4*5), there are mainly 5 steps (we use brackets to note every part of the expression):
1. Check the syntax, no syntax errors.
2. Fetch the highest priority operator 4, no errors.
3. Do arithmetic -(4), get result -4, no errors.
4. Do arithmetic (-(4))*(5), get result -20, no errors.
5. Because operator “^” has right associativity, we do arithmetic (3)^((-(4))*(5)), e.g. (3)^(-20) first. -20 is a negative number, and negative numbers are not allowed as an exponent, so the calculator simply outputs error message and stops.
Notes: Because “-“ has two meanings, the calculator will treat it as an unary operation at first,
and if it fails, “-“ would be treated as minus operation then.
Write a program to simulate the calculator.

Input
The first line of the input file is an integer T<=200, then following T test cases.
Each test case has only one line, the input expression given to the calculator. Each expression has no more than 2000 characters.

Output
For each test case, output one line contains the case number and the final result or “ERROR!” if any error occurs. See sample for detailed format.

Sample Input
6
2^(1 2 - 9)^(5%3)
9-8**7
4%(2^0-1)
-5%-3+-5%3
7^--100
(7-3)^(3-7)

Sample Output
Case 1: 512
Case 2: ERROR!
Case 3: ERROR!
Case 4: -4
Case 5: ERROR!
Case 6: ERROR!

  • 写回答

0条回答 默认 最新

    报告相同问题?

    悬赏问题

    • ¥15 (关键词-电路设计)
    • ¥15 如何解决MIPS计算是否溢出
    • ¥15 vue中我代理了iframe,iframe却走的是路由,没有显示该显示的网站,这个该如何处理
    • ¥15 操作系统相关算法中while();的含义
    • ¥15 CNVcaller安装后无法找到文件
    • ¥15 visual studio2022中文乱码无法解决
    • ¥15 关于华为5g模块mh5000-31接线问题
    • ¥15 keil L6007U报错
    • ¥15 webapi 发布到iis后无法访问
    • ¥15 初学者如何快速上手学习stm32?