The instructions of a program can be categorized into four types, A, B, C, and D. Type A consists of 100 instructions, Type B consists of 150 instructions, Type C consists of 250 instructions, and Type D consists of 500 instructions. In the instruction set, each instruction takes the same amount of time to execute. The entire program takes 1000 seconds to run. What is the improved execution time if the Type D instructions are improved by a factor of 2

Given the following code: if (n == 2) { k -= 2; } else if (n == 3) { k -= 3; } can be rewritten as: if (< condition > ) { < assignment statement > ; } assume that evaluating < condition > does not change the values stored in n and k. which of the following could be used as < assignment statement > ? k -= n; k -= 1; k -= 2; k += n; k = n - k;

Pthreads programming: create and terminate a thread write a c++ program that creates a thread. the main will display a message “hello world from the main”. the main will create a thread that will display a message “hello world from the thread” and then terminates with a call to pthread_exit()

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';