tasks a-s

Task/Roman-numerals-Encode/Smalltalk/roman-numerals-encode-1.st

@@ -0,0 +1 @@
+2013 printRomanOn:Stdout naive:false

Task/Roman-numerals-Encode/Smalltalk/roman-numerals-encode-2.st

@@ -0,0 +1,53 @@
+printRomanOn:aStream naive:naive
+    "print the receiver as roman number to the argument, aStream.
+     The naive argument controls if the conversion is
+     correct (i.e. subtracting prefix notation for 4,9,40,90, etc.),
+     or naive (i.e. print 4 as IIII and 9 as VIIII); also called simple.
+     The naive version is often used for page numbers in documents."
+
+    |restValue spec|
+
+    restValue := self.
+    restValue > 0 ifFalse:[self error:'negative roman'].
+
+    naive ifTrue:[
+        spec := #(
+                " value string repeat "
+                   1000 'M'    true
+                    500 'D'    false
+                    100 'C'    true
+                     50 'L'    false
+                     10 'X'    true
+                      5 'V'    false
+                      1 'I'    true
+                 ).
+    ] ifFalse:[
+        spec := #(
+                " value string repeat "
+                   1000 'M'    true
+                    900 'CM'   false
+                    500 'D'    false
+                    400 'CD'   false
+                    100 'C'    true
+                     90 'XC'   false
+                     50 'L'    false
+                     40 'XL'   false
+                     10 'X'    true
+                      9 'IX'   false
+                      5 'V'    false
+                      4 'IV'   false
+                      1 'I'    true
+                 ).
+    ].
+
+    spec
+        inGroupsOf:3
+        do:[:rValue :rString :repeatFlag |
+
+            [
+                (restValue >= rValue) ifTrue:[
+                    aStream nextPutAll:rString.
+                    restValue := restValue - rValue.
+                ].
+            ] doWhile:[ repeatFlag and:[ restValue >= rValue] ].
+        ].