You need a program (in C programming language) that should read ".txt" file and count how many lower case in the file but it should count one by one (calculate probabilities of all letters) and write to screen all of results.
For example, p(a)=0.123, p(b)=0.053 etc.
Additionally, this program should calculate p(aa), p(bb) and p(a|a), p(a|b) possibilities [Joint and Conditional probabilities] and lastly, the program should calculate all entropies for each possibilities and write to screen all of results.