Using the grammar for real-number constants discussed in class, write a set of rewrite rules for signed real-number constants that allow an optional sign at the front of the constants. Use signed-real-const as the new start symbol. You can reuse as much or as little of the real-number constant grammar rules as you deem appropriate. Examples of valid signed real-number constants are:

Write an application that allows a user to enter the names and birthdates of up to 10 friends. continue to prompt the user for names and birthdates until the user enters the sentinel value “zzz” for a name or has entered 10 names, whichever comes first. when the user is finished entering names, produce a count of how many names were entered, and then display the names. in a loop, continuously ask the user to type one of the names and display the corresponding birthdate or an error message if the name has not been previously entered. the loop continues until the user enters “zzz” for a name. save the application as birthdayreminder.java.

Is a string of code written to hurt others by damaging or destroying

We as humans write math expression in infix notation, e.g. 5 + 2 (the operators are written in-between the operands). in a computer’s language, however, it is preferred to have the operators on the right side of the operands, i.e. 5 2 +. for more complex expressions that include parenthesis and multiple operators, a compiler has to convert the expression into postfix first and then evaluate the resulting postfix.write a program that takes an “infix” expression as input, uses stacks to convert it into postfix expression, and finally evaluates it. it must support the following operations: + - / * ^ % (example infix expression: (7 - 3) / (2 + 2)postfix expression: 7 3 - 2 2 + /result: 1guidelines: 1. you will need to use stacks in three placesa. one for the parenthesis check [char stack]b. one during infix to postfix [char stack]c. one during evaluation [int stack]for a and b above, you can use same array and same push, pop method as both ofthem are char. but for evaluation you have int stack and you might consider to createanother push pop method to handle it. maybe push_int, pop_int, etc. or find otherstrategy to utilize existing push pop method2. you can create a function for obtaining operator priority. that function should take anoperator as input and return its priority as an integer. this function will you a lot andreduce repeated code3. during evaluation you will need to convert char into integer. example for single digit: char c = '5'; int x = c - '0';