provide three different input stream classes for C++

Write a value function in a C++ program that has two double parameters, calculates their difference, and returns the absolute value of the difference?

Pls make a code for this on c++ and make sure it is 100% correct. i wastred 4 questoins on this  and they all are not correct.  Write the code as described in the questions below. Submit your code electronically in the box at the bottom. You may only use Java, C# or C++. The economy is defined using a 2-dimensional data structure:   A “payday” will be considered to be any region of $ values where all cells in the region are connected either vertically or horizontally. For example, the following illustrates a matrix with 5 rows and 8 columns containing three objects. $’s and P are used in the diagram to represent the two types of values: PPPP$PPPPPP$$PPPPP$$PPP$PP$PPPP$P$PPP$$$ a)   Write a program to read in the data from the text file and store it into a data structure. Your program should output it to the screen after it has read in the file. (If you can’t get this to work hard-code the above example and continue to part b). Here is a sample text file (containing the above data):…

List two features we used from the C++ standard library, including a short explanation of why you would use the feature and which header file must be included. Example: The std::cin object is found in the iostream header file and is used to read characters from the keyboard.