1. 其他
2. C/C++
3. 其他
4. 其他
5. 沒有
描述： 1. 學校作業
2. 大二生找專題教授
3. 就把這題寫出來就好
4. Description.
The engineering calculator serves as a handy tool for performing calculations related to
complex formulas. The following instructions provide tips for implementing the basic
functionality of the calculator. Now, follow these instructions and proceed to code the
calculator.
1. Design a calculator that can evaluate any expressions. ( ※ Include +, -, *, /, (, ), ^ )
[Ex.] ( 1.2 + 2.3 ) * ( ( 3.4 / 4.5 ) / ( ( - 0.6 ) + 7 * ( 1 - 1 ) ) ) ^ 2
[Ans.] 5.55007
2. Extend the calculator such that it can deal with sin, cos, tan, exp, log ... etc.
( ※ The units for sin and cos are degrees, and the base used for log is 10. )
[Ex.] sin ( cos 0 + 89 ) + cos 90 - log ( 1000 / 10 ) + exp 2
[Ans.] 6.38906
Note.
You can implement more symbols, but please include at least all the symbols
mentioned above.
3. Extend the calculator such that the program can handle multiple statements and print
out the values for all variables.
[Ex.]
int a, b, c ;
float d, e ;
// integer variables
// float variables
a = 5 ;
b = 7 ;
c = ( 12 + 23 ) / ( a + 12 ) * ( b + 8 ) ;
d = c + 1.2 + sin 45 ;
e = d + b * 5.6 ;
[Ans.]
( a, b, c, d, e ) = ( 5, 7, 30, 31.907, 71.107 )
Note.
We can ensure that the variable types are limited to int and float, and the calculated
float results should be rounded to 3 decimal places.
Requirements.
1. Implement your program using C or C++
2. Your program can be executed in two ways:
A. After your user execute your program, let the user choose the mode. If the user
chooses Direct Mode, you have to let the user type in formula then output the result
on terminal.
[Ex.] {Assume that your program named “calculator”}
$ ./calculator
Choose your mode: direct
sin 90 + cos 0
2
B. The other mode user can choose is the File Mode. In this one you will let the user
type input file name, output file name respectively. Do the calculation on input file
then output them on output file.
[Ex.] {Assume that your program named “calculator”}
$ ./calculator
Choose your mode: file
Input file name: input.txt
Output file name: output.txt
3. The file format for input and output will only be *.txt
4. User could add comment by using //, or /*, */ . Please remove it before starting your
calculation methods.
5. If the user encounters any illegal errors (as divide 0, using variable unassigned, wrong
symbols), please output an error message (the format can be arbitrary).
6. Please write a README or Report to introduce how to use your program and provide
information on its implementation
Examples.
1. Direct Computation Mode
In [1]：./calculator
Choose your mode: Direct
0+1
Out[1]：1
In [2]：./calculator
Choose your mode: direct
tan(90)
Out[2]：infinity
* The format of Infinity can be arbitrary
In [3]：./calculator -d
Choose your mode: direct
0++3
Out[3]：error
* The format of error can be arbitrary
In [4]：./calculator
Choose your mode: direct
2 ^ 2 * exp ( 1.0 + 2.0 / 2 ) + 3.14159 * sin ( 89 + cos ( -0.0 ))
Out[4]：403.142
2. File Mode
In [1]：./calculator
Choose your mode: file
Input file name: in1.txt
Output file name: out1.txt
in1.txt：
* Remember remove the comments
int a, b, c; // integer variables
float d,e ; // float variables
a = 5 ;
b = 7 ;
c = (12 +23) / (a + 12) * (b + 8);
d = c + 1.2 + sin 45;
e = d + b * 5.6;
out1.txt：
(a, b, c, d, e) = (5, 7, 30, 31.907, 71.107)
* The format of output can be arbitrary
In [2]：./calculator
Choose your mode: file
Input file name: in2.txt
Output file name: out2.txt
in2.txt：
* Remember remove the comments
int a, b; /* integer variables */
float f, g, d, h, c; /* float variables */
a = 5 ;
b = 7 ;
c = (12 +23) / (a + 12) * (b + 8);
d = (exp2+32)/6;
f = c + 1.2 + sin 45;
g = d + b * 5.6;
out2.txt：
(a, b, f, g, d, h, c) = (5, 7, 32.789, 61.200, 22.000, 0.000, 30.882)
* The format of output can be arbitrary
Hints.
1. If you encounter difficulties dealing with string-related issues, such as unnecessary
whitespace or the need to remove comments, you can address your problems using
regex notation. ( https://regex101.com/ )
2. In terms of computation, utilizing Post-order Traversal can be highly beneficial for
calculations.
3. If it is indeed challenging to implement two functionalities in the same executable,
consider creating separate executables for each functionality (an executable for
Direct Computation Mode and another for File Mode).
5. 三天內
