My Mac is stuck on this screen? How to fix?

Which of the following is a way the operating system prevents unknown or unauthorized users from accessing the system?

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';

Cengagenowv2 is a comprehensive online learning tool. using cengagenowv2, you may access all of the following except: 2. each time you log in, cengagenowv2 automatically performs a system check and informs you if your computer does not meet the cengagenowv2 system requirements. 3. which tab/page allows you to easily track your assignment scores, number of submissions, time spent, as well as the ability view assign