Define a class Name_value that holds a string and a value. Rework exercise 19 in Chapter 4 to use a vector instead of two vectors.

Dara from Exercise 19

Write a program where you first enter a set of name-and-value pairs, such as Joe 17 and Barbara 22. For each pair, add the name to a vector called names and the number to a vector called scores (in corresponding positions, so that if names[7]=="Joe" then scores[7]==17). Terminate input with NoName 0. Check that each name is unique and terminate with an error message if a name is entered twice. Write out all the (name,score) pairs, one per line.