Write a program in C language with output examples that:

Open an existing text file (with line breaks; each line is shorter than 150 characters),

Read the file,

Count the frequency of each word in the file, and

Print the 75 most frequently used words to stdout in the decreasing order of their frequency.

The length of the file is not limited. A word is defined as a sequence of non-blank characters (punctuation ok), with all letters converted to upper case. A frequency of a word shall be defined as the number of instances of the word in the text.

The name of the text file shall be passed as the first command line parameter. The program shall deallocate (free) all memory that it has allocated.