please use C++ programming

Write a function that accepts a pointer to a C-string as an argument and returns the number of words contained in the string.

For instance, if the string argument is Four score and seven years ago the function should return the number 6.

Demonstrate the function in a program that asks the user to input a string or a file.

If the user enters a file, read the file, and submits each sentence to the function.

Write a second function that determines the average length of the words in a sentence.

For each sentence or user-entered phrase, display: the number of words and the average length of the words.