Chapter 17, Problem 4PC

File Encryption and Decryption

Write a program that uses a map to assign “codes” to each letter of the alphabet. For example:

map<char, char> codes =

{ {‘A’, ‘%’}{‘a’,     ‘9’}, {‘B’, ‘@’}, {‘b’ , ‘#'}, etc...};

Using this example, the letter ‘A’ would be assigned the symbol %, the letter ‘a’ would be assigned the number 9, the letter ‘B’ would be assigned the symbol @, and so forth. The program should open a specified text file, read its contents, then use the map to write an encrypted version of the file’s contents to a second file. Each character in the second file should contain the code for the corresponding character in the first file. Write a second program that opens an encrypted file and displays its decrypted contents on the screen.