War Games: A Nuclear Simulation

wargames.scm

;;; Rishi Goutam; War Games

; Global variables

; Cities - get name by car and population by cdr of (assoc 'name cities)
(define cities '((Shanghai . 14) (Mumbai . 14) (Karachi . 13) (Delhi . 13) (Istanbul . 13) (Moscow. 13) (Seoul . 12) (Beijing . 10) (Jakarta . 10) (Tokyo . 9) (Kinshasa . 9) (Lagos . 8) (Lima . 8) (London . 8) (Bogota . 7) (Tehran . 7) (Bangkok . 7) (Dhaka . 7) (Cairo . 7) (Hanoi . 7) (Lahore . 6) (Chongqing . 5) (Bangalore . 5) (Tianjin . 5) (Baghdad . 5) (Kolkata . 5) (Singapore . 5) (Santiago . 5) (Riyadh . 5) (Surat . 5) (Chicago . 3) (Seattle . 1) (Boston . 1)))

; Invalid targets - should not annihilate American cities
(define american-cities '((Seattle . 1) (Boston . 1) (Chicago . 3)))

; presidential password
(define passwd 'JOSHUA)

; logged in
(define logged-in #f)

; starting number of bombs
(define bombs 3)

; the main program loop. run this to simulate a nuclear scenario
(define (wargames)
  (define (repl)
    (newline)
    (begin
      ; user interface changes whether logged in
      (if logged-in
          (display "Input a command: BOMB-CITY, LOGOUT, BOMBS, CITIES, SHOW-MAP ")
          (display "Input a command: LOGIN, CITIES, SHOW-MAP "))
      (let ((command (read)))
        ; assign each command to its helper
        (begin
          (cond ((eq? 'LOGIN command)     (process-login))
                ((eq? 'BOMB-CITY command) (process-bomb-city))
                ((eq? 'LOGOUT command)    (process-logout))
                ((eq? 'SHOW-MAP command)  (process-show-map))         ; always accessible
                ((eq? 'CITIES command)    (display cities) (newline)) ; always accessible
                ((eq? 'BOMBS command)     (process-bombs))
                (else
                 (display "Not a valid command.")))
          (repl))))); REPL wargames
  (display "Would you like to play a game? ")
  (let ((play-game (read)))
    (if (or (eq? 'y play-game) (eq? 'yes play-game))
        (begin
          (newline) ; RULES
          (display "War Operation Plan Response allows you to target cities\n")
          (display "but prevents you from making an invalid selection to\n")
          (display "Each missile dropped on a city reduces the population by 3 million\n")
          (repl))
        ; Quits the REPL loop.
        (begin
          (display "A strange game. \n")
          (display "The only winning move is\n")
          (display "not to play.\n")))))

; COMMAND helpers

; logs the president out
(define (process-logout)
  (if logged-in
      (begin
        (display "Goodbye, Mr. President.\n")
        (set! logged-in #f))
      (display "You are not logged in. Please do so.\n")))


; logs the president in
(define (process-login)
  (if logged-in
      (display "Silly President. You are already logged in!")
      (begin
        (display "Type in the password, Mr. President: ")
        (begin
          (let ((user-password (read)))
            (if (eq? user-password passwd)
                (begin
                  (set! logged-in #t)
                  (display "Welcome, Mr. President. You are now logged in."))
                (display "Incorrect password.")))
          (newline)))))

; bombs a city that the user inputs. must be logged in as the president
(define (process-bomb-city)
  (if logged-in
      (begin
        (display "Enter a city to bomb from CITIES.\n")
        (let ((city (read)))
          (if (assoc city cities)
              (if (assoc city american-cities)
                  (display "War Operation Plan Response will not bomb American cities.\n")
                  (let* ((pair (assoc city cities))
                         (population (cdr pair)))
                    (cond ((= 0 population)
                           (display "This city has no inhabitants. No bomb has been dropped.\n"))
                          ((= 0 bombs)
                           (display "You do not possess any bombs. No bomb has been dropped.\n"))
                          (else
                           (begin
                             (set! bombs (- bombs 1))
                             (if (< population 3)
                                 (set! cities (cons (cons city 0) cities))
                                 (set! cities (cons (cons city (- population 3)) cities)))
                             (display "You have bombed the city and killed 3 million inhabitants."))))))
              (display "This city exists only in your imagination.\n"))))
      (display "You are not logged in. Please do so.\n")))

; shows number of bombs remaining
(define (process-bombs)
  (if logged-in
      (begin (display bombs) (newline))
      (display "You are not logged in. Please do so.")))

; display an ASCII world map
(define (process-show-map)
  (display "``````````````````~?????=+?????=~````````=```````+?``````?``````````````````````\n")
  (display "`````````````?++`?~?~`???????????```````?~````````````````??````````````````````\n")
  (display "````````````??==????`````????????````````````````?``````?????=`````?~?``````````\n")
  (display "``````````?~??~`+`???+```???????~`````````~``````?``??????????????????~=````?```\n")
  (display "`???????????~`?++?~=???```????``````````+?????``?????????????????????????????=``\n")
  (display "?`????????????????=+~`=```??```````````??`??????????????????????????????????````\n")
  (display "``??```??????????```??`~````````````~`?`?`??????????????????????????````````````\n")
  (display "`~``````=??????????`????+``````````?```????????????777??????`???????```?````````\n")
  (display "``````````????????????=?`?```````````??????????777777777????????????``~`````````\n")
  (display "``````````????????+~+?~``````````````???~???`~?=77=7777???????????+`?```````````\n")
  (display "``````````???????????``````````````??~```~~????=`7777??????????`?``?````````````\n")
  (display "```````````+????????```````````````IIII?`````=====7777?????????``?``````````````\n")
  (display "````````````????```?``````````````?IIIIIIIII=======77777I7?????~````````````````\n")
  (display "``````````````??```?``````````````IIIIIIIIIII`====``77777?????``````````````````\n")
  (display "````````````````??````````````````IIIIIIIIIIII`==````77```??+``?````````````````\n")
  (display "`````````````````````+~=``````````IIIIIIIIIIIIII``````?`````=```````````````````\n")
  (display "````````````````````++++++`````````?``IIIIIIIIII``````````??``?`````````````````\n")
  (display "````````````````````++++++=~```````````IIIII`I`````````````?`?+?+~``````````````\n")
  (display "````````````````````++++++++++``````````IIIIII``````````````??``~``??``~````````\n")
  (display "`````````````````````++++++++```````````IIIIII```````````````````??`````````````\n")
  (display "``````````````````````+++++++```````````IIIII``I```````````````??????```````````\n")
  (display "``````````````````````+++++`````````````IIII=`````````````````????????~`````````\n")
  (display "``````````````````````++++```````````````III``````````````````????????~`````````\n")
  (display "`````````````````````++++```````````````````````````````````````````??``````````\n")
  (display "`````````````````````++```````````````````````````````````````````````````?`````\n")
  (display "`````````````````````++`````````````````````````````````````````````````````````\n")
  (display "`````````````````````+``````````````````````````````````````````````````````````\n")
  (display "````````````````````````````````````````````````````````````````````````````````\n"))

; starts an instance of wargames
(wargames)