EMuller_Leap_Year

globals [
  days            ;; a list of the dates of all 365 days in the year
  successes       ;; how many ticks had at least one duplicate birthday
  lysuccesses
]

turtles-own [
  birthday        ;; this turtle's birthday as a number from 0 to 364
  lybirthday      ;; this turtle's birthday as a number from 0 to 365
]

to setup
  clear-all
  set successes 0
  ;; create lists of each month and the number of days in each month
  ;; then iterate through the two lists and expand into a single list
  ;; of every day of the year
  let months ["January" "February" "March" "April" "May" "June" "July"
              "August" "September" "October" "November" "December"]
  let month-lengths [31 28 31 30 31 30 31 31 30 31 30 31]
  ;; now build up the list of all the day names in the year
  set days []
  ;; sets ?1 equal each month name and ?2 to the number of days in that month
  (foreach months month-lengths
  [ ;; use "sentence" to repeatedly glue lists together, so we wind
    ;; up with one big list
    set days (sentence days make-month ?1 ?2)
  ])
  reset-ticks
end 

to leapyear
    clear-all
  set successes 0
  ;; create lists of each month and the number of days in each month
  ;; then iterate through the two lists and expand into a single list
  ;; of every day of the year
  let months ["January" "February" "March" "April" "May" "June" "July"
              "August" "September" "October" "November" "December"]
  let month-lengths [31 29 31 30 31 30 31 31 30 31 30 31]
  ;; now build up the list of all the day names in the year
  set days []
  ;; sets ?1 equal each month name and ?2 to the number of days in that month
  (foreach months month-lengths
  [ ;; use "sentence" to repeatedly glue lists together, so we wind
    ;; up with one big list
    set days (sentence days make-month ?1 ?2)
  ])

  reset-ticks
end 


;; this procedure generates all of the day names within a month

to-report make-month [month month-length]
  ;; use n-values to generate a list of the numbers from 1 to
  ;; the end of the month
  let day-numbers n-values month-length [? + 1]
  ;; now glue onto the month name each number
  report map [(word month " " ?)] day-numbers
end 

to go
  ;; kill off the turtles from the last round
  clear-turtles
  ;; populate the room with new turtles
  make-turtles
  ;; arrange the turtles in order by birthday
  sort-turtles
  ;; turn turtles with matching birthdays green
  show-matches
  ;; keep track of cumulative results
  if any? turtles with [color = green]
    [ set successes successes + 1 ]
  if any? turtles with [color = red]
    [ set lysuccesses lysuccesses + 1 ]
  tick
end 

to make-turtles
  ;; ask the patches along the right edge of the world
  ;; to each sprout a turtle
  ask patches with [pxcor = max-pxcor]
  [
    sprout 1
    [
      set heading 90
      set color blue + 3
      ;; pick a random birthday (a number from 0 to 364)
      set birthday random length days
      ;; we use "word" to add some spaces onto the end
      ;; of the turtle's labels, otherwise the label
      ;; would visually overlap the turtle.  ITEM
      ;; is used to look up our day name in the list
      ;; of all day names.
       set label word (item birthday days) "        "
      set lybirthday 60
     ]
   ]
end 

to sort-turtles
  ;; sort-by takes an agentset and returns a sorted list
  let sorted sort-on [birthday] turtles
  ;; finally, we position each turtle according to its position
  ;; in the sorted list
  ask turtles
    [ set ycor max-pycor - position self sorted ]
end 

to show-matches
  ;; if there are any turtles with the same birthday
  ;; show it.
  ask turtles
    [ if any? other turtles with [birthday = [birthday] of myself]
        [ set color green
          set label-color green ] ]
  ask turtles
    [ if any? other turtles with [birthday = [lybirthday] of myself]
        [ set color red
          set label-color red ] ]
end 


; Copyright 2004 Uri Wilensky.
; See Info tab for full copyright and license.