please explain the code in a orgnized way

Q4. In this programming assignment, you will first design using pseudo code two versions of arithmetic calculators. The first version will be based on the pseudo code discussed in class that uses two different stacks. The second version must be completely based on recursion and must not use any stack (however, we know by now that recursion will implicitly use JVM's own stack as in regular function calls). You will implement the first version in Java. Your arithmetic calculators must read lines of text from a text file, where each line contains a syntactically correct arithmetic COMP 352 -Winter 2018 Assignment 2 - page 1 of2 expression. Your output file must repeat the input line and print the computed result on the next line. Your calculators must support the following operators on integers and observe the standard operator precedence as shown in the following (1 to 8: 1 is highest and 8 is lowest. Same precedence operators are evaluated from left to right) 1. Parentheses (possibly nested ones): () Unary operators 2. factorial:! 3. minus: - Binary operators: 4. power function: xy 5. operators: *, / 6. operators: +, - 7, operators. > 8. operators