Question: Write a program that will read a line of text that ends with a period, which serves as a sentinel value. Display all the letters that occur in the next, one per line and in alphabetical order, along with the number of times each letters occurs in the next. Use an array of base type int of the length 26, so that the element at index 0 contains the number of a's, the element at index 1 contains the number of b"s, and so forth. Allow both uppercase and lowercase letters.

As input, but treat uppercase and lowercase versions of the same letter as being equal.

Allow the user to repeat this task until the user says she or he is through.