Implement a program that implements a substitution cipher, per the below.
$ ./substitution JTREKYAVOGDXPSNCUIZLFBMWHQ
plaintext: HELLO
ciphertext: VKXXN
Substitution - CS50
Implement a program that implements a substitution cipher, per the below.
$ ./substitution JTREKYAVOGDXPSNCUIZLFBMWHQ
plaintext: HELLO
ciphertext: VKXXN
Substitution - CS50