In reverse Polish notation the operators follow their operands. To add 3 and 4, one would write "3 4+" rather than "3 + 4". If there are multiple operations, the operator is given immediately after its second operand. The expression written "3 - 4 + 5" would be written "3 4- 5 +" in RPN: first subtract 4 from 3, then add 5 to that. An advantage of RPN is that it obviates the need for parentheses that are required by infix notation.
Your assignment is to produce a Reverse Polish Notation calculator that operates on input files.
1. First, ask the userfor the location of an input text file. Open this file.
2. Read in the input text file, and interpret the input data as RPN. Each line in the file should be interpreted as its own math problem.
3. Display theresulting answers to the screen, with each output line corresponding to the input lines.
4. If a math problem has an error in its syntax, display SYNTAX ERROR for that line and continue with the next problem.
Do not support unary operators. The user will not beable to enter negative numbers. (However, your program must still be able to handle internal numbers that are negative and negative results.)
Add support for the following binary operators, written exactly as shown: + - * / % pow
The pow operator should raise the first operand to the power of the second operand. The % operator should perform modulo division. The C standard library supports modulo division of floating point numbers, whereas the built-in C++ modulo division operator only supports integer division. You will need to usethe library function in order to handle the potential decimal number inputs from the user.
Support decimal number inputs as well as integer number inputs.
Implement operators using good object oriented design techniques. Represent each type of data the user could enter as a class. There should be anoperandclass that represents anumber, and several classes that inherit froma base class ofoperator, which represents each operator implemented. The base operatorclass should have a function that applies the operator to two operands that are passed in as arguments to the function. Each operator class that inherits should then override the function with one that actually performs that operation. Each child class should also have agetter that returns the operator symbol.Allof these classes should inherit from a common ancestor class namedsymbol. Example boilerplate code follows:
class symbol { };
class operand : public symbol { ... };
class operator : public symbol { ... };
class add : public operator { ... };
...
class pow : public operator { ... };
You should take the input expressions and create the appropriate classes to represent the input data, and then run the functions on that data to obtain your result.
You maynotstore type information about the classes in the classes themselves. i.e. Do not do what we did with the type field in rock/paper/scissors.
Your project submission should be logically laid out and use good object oriented design. Pretend that this project might one day be extended by additional developers by adding additional operators or other features. Points may be deducted if your assignment does not allow for flexibility in the program.
There will be oneor more whitespace characters between two numbers. There will be zeroor more whitespace characters between a number and a symbol or two symbols.
Sample Input:
3 4 5.0 * -
7
4. * 8 30 +
banana
9 10 + 30 -
4. 7 3-+ 2 -3+
900 40.65- 20 +
45.2 23.999%
Sample Output:
-17
7
SYNTAX ERROR
SYNTAX ERROR
-11
9
879.35
21.201