Please only solve using C++

Given a language with letter alphabet , of size n = ||, the entropy of the letters is Hu = log n if all n letters of the alphabet are equally probable. In actual use of the language, this might not be the case and the computed entropy Hexp from texts of the language would be different from Hu. The letter redundancy of the language may be taken as R = 1- Hexp / Hu. This means that only m = (1 R)n letters can be used effectively to write most of the language texts.

The Screenshot below gives the letter frequencies observed for four different languages (Arabic, English, French and Greek). Given these frequencies, compute Hexp for the given four languages and compare between their redundancies.