C programming language

You should write a program that reads the book you have downloaded. Program will request 4 characters from the user and will delete the words starting with this character. Program should continue to request character until the entered character is a letter. In addition, your program will request 4 words from the user and change these words with the 4 most occurred word in the text, respectively. You should do this operation after you have deleted the words starting with the entered letters. At the end, program will save the new text into separate text file. For example, entered characters are y,h,s,u. First program will delete all words starting with these letters. Then, the entered words are he, she, we, they and the program will replace the entered words with 4 most occurred word (e.g. 1, you, your, their) in the text, respectively (e.g. he, she--you, we-your, they their). You are not allowed to use string.h library. You should allocate memory dynamically. All operations should not be done in the main function. You must use at least one more function besides main(). You should write a program that reads the book you have downloaded. Program will request 4 characters from the user and will delete the words starting with this character. Program should continue to request character until the entered character is a letter. In addition, your program will request 4 words from the user and change these words with the 4 most occurred word in the text, respectively. You should do this operation after you have deleted the words starting with the entered letters. At the end, program will save the new text into separate text file. For example, entered characters are y,h,s,u. First program will delete all words starting with these letters. Then, the entered words are he, she, we, they and the program will replace the entered words with 4 most occurred word (e.g. 1, you, your, their) in the text, respectively (e.g. he, she--you, we-your, they their). You are not allowed to use string.h library. You should allocate memory dynamically. All operations should not be done in the main function. You must use at least one more function besides main()