Write a program that will read a line of text and output a list of all the letters that occur in the text together with the number of times each letter occurs in the line. End the line with a period that serves as a sentinel value. The letters should be listed in the following order: the most frequently occurring letter, the next most frequently occurring letter, and so forth. Use two arrays, one to hold integers and one to hold letters.

You may assume that the input uses all lowercase letters. For example,

the input

do be do bo.

should produce output similar to the following:

Letter Number of Occurrences

o 3

d 2

b 2

e 1

Your program will need to sort the arrays according to the values in the

integer array. This will require that you modify the function sort given

in Display 7.12. You cannot use sort to solve this problem without

changing the function. If this is a class assignment, ask your instructor if

input/output should be done with the keyboard and screen or if it

should be done with files. If it is to be done with files, ask your

instructor for instructions on file names.