September Morn Update

Task/Roman-numerals-Encode/Python/roman-numerals-encode-4.py

@@ -1,11 +1,22 @@
-rnl = [ { '4' : 'MMMM', '3' : 'MMM', '2' : 'MM', '1' : 'M', '0' : '' }, { '9' : 'CM', '8' : 'DCCC', '7' : 'DCC',
-          '6' : 'DC', '5' : 'D', '4' : 'CD', '3' : 'CCC', '2' : 'CC', '1' : 'C', '0' : '' }, { '9' : 'XC',
-          '8' : 'LXXX', '7' : 'LXX', '6' : 'LX', '5' : 'L', '4' : 'XL', '3' : 'XXX', '2' : 'XX', '1' : 'X',
-          '0' : '' }, { '9' : 'IX', '8' : 'VIII', '7' : 'VII', '6' : 'VI', '5' : 'V', '4' : 'IV', '3' : 'III',
-          '2' : 'II', '1' : 'I', '0' : '' }]
-# Option 1
-def number2romannumeral(n):
-    return ''.join([rnl[x][y] for x, y in zip(range(4), str(n).zfill(4)) if n < 5000 and n > -1])
-# Option 2
-def number2romannumeral(n):
-    return reduce(lambda x, y: x + y, map(lambda x, y: rnl[x][y], range(4), str(n).zfill(4))) if -1 < n < 5000 else None
+def arabic_to_roman(dclxvi):
+#===========================
+  '''Convert an integer from the decimal notation to the Roman notation'''
+  org = dclxvi; # 666 #
+  out = "";
+  for scale, arabic_scale  in enumerate(arabic):
+    if org == 0: break
+    multiples = org // arabic_scale;
+    org -= arabic_scale * multiples;
+    out += roman[scale] * multiples;
+    if (org >= -adjust_arabic[scale] + arabic_scale):
+      org -= -adjust_arabic[scale] + arabic_scale;
+      out +=  adjust_roman[scale] +  roman[scale]
+  return out
+
+if __name__ == "__main__":
+  test = (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,25,30,40,50,60,69,70,
+     80,90,99,100,200,300,400,500,600,666,700,800,900,1000,1009,1444,1666,1945,1997,1999,
+     2000,2008,2500,3000,4000,4999,5000,6666,10000,50000,100000,500000,1000000);
+
+  for val in test:
+    print("%8d %s" %(val, arabic_to_roman(val)))

Task/Roman-numerals-Encode/Python/roman-numerals-encode-5.py

@@ -1,22 +1,11 @@
-def arabic_to_roman(dclxvi):
-#===========================
-  '''Convert an integer from the decimal notation to the Roman notation'''
-  org = dclxvi; # 666 #
-  out = "";
-  for scale, arabic_scale  in enumerate(arabic):
-    if org == 0: break
-    multiples = org // arabic_scale;
-    org -= arabic_scale * multiples;
-    out += roman[scale] * multiples;
-    if (org >= -adjust_arabic[scale] + arabic_scale):
-      org -= -adjust_arabic[scale] + arabic_scale;
-      out +=  adjust_roman[scale] +  roman[scale]
-  return out
-
-if __name__ == "__main__":
-  test = (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,25,30,40,50,60,69,70,
-     80,90,99,100,200,300,400,500,600,666,700,800,900,1000,1009,1444,1666,1945,1997,1999,
-     2000,2008,2500,3000,4000,4999,5000,6666,10000,50000,100000,500000,1000000);
-
-  for val in test:
-    print("%8d %s" %(val, arabic_to_roman(val)))
+rnl = [ { '4' : 'MMMM', '3' : 'MMM', '2' : 'MM', '1' : 'M', '0' : '' }, { '9' : 'CM', '8' : 'DCCC', '7' : 'DCC',
+          '6' : 'DC', '5' : 'D', '4' : 'CD', '3' : 'CCC', '2' : 'CC', '1' : 'C', '0' : '' }, { '9' : 'XC',
+          '8' : 'LXXX', '7' : 'LXX', '6' : 'LX', '5' : 'L', '4' : 'XL', '3' : 'XXX', '2' : 'XX', '1' : 'X',
+          '0' : '' }, { '9' : 'IX', '8' : 'VIII', '7' : 'VII', '6' : 'VI', '5' : 'V', '4' : 'IV', '3' : 'III',
+          '2' : 'II', '1' : 'I', '0' : '' }]
+# Option 1
+def number2romannumeral(n):
+    return ''.join([rnl[x][y] for x, y in zip(range(4), str(n).zfill(4)) if n < 5000 and n > -1])
+# Option 2
+def number2romannumeral(n):
+    return reduce(lambda x, y: x + y, map(lambda x, y: rnl[x][y], range(4), str(n).zfill(4))) if -1 < n < 5000 else None

Task/Roman-numerals-Encode/Python/roman-numerals-encode-6.py

@@ -0,0 +1,64 @@
+'''Encoding Roman Numerals'''
+
+from functools import reduce
+from itertools import chain
+
+
+# romanFromInt ::  Int -> String
+def romanFromInt(n):
+    '''A string of Roman numerals encoding an integer.'''
+    def go(a, ms):
+        m, s = ms
+        q, r = divmod(a, m)
+        return (r, s * q)
+    return concat(snd(mapAccumL(go)(n)(
+        zip([1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1],
+            ['M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX',
+             'V', 'IV', 'I'])
+    )))
+
+
+# MAIN -------------------------------------------------
+# main :: IO ()
+def main():
+    '''Test'''
+    print(
+        list(map(romanFromInt, [1666, 1990, 2008, 2016, 2018]))
+    )
+
+
+# GENERIC FUNCTIONS ---------------------------------------
+
+# concat :: [[a]] -> [a]
+# concat :: [String] -> String
+def concat(xxs):
+    '''The concatenation of all the elements in a list.'''
+    xs = list(chain.from_iterable(xxs))
+    unit = '' if isinstance(xs, str) else []
+    return unit if not xs else (
+        ''.join(xs) if isinstance(xs[0], str) else xs
+    )
+
+
+# mapAccumL :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])
+def mapAccumL(f):
+    '''A tuple of an accumulation and a list derived by a
+       combined map and fold,
+       with accumulation from left to right.'''
+    def go(a, x):
+        tpl = f(a[0], x)
+        return (tpl[0], a[1] + [tpl[1]])
+    return lambda acc: lambda xs: (
+        reduce(go, xs, (acc, []))
+    )
+
+
+# snd :: (a, b) -> b
+def snd(tpl):
+    '''Second component of a tuple.'''
+    return tpl[1]
+
+
+# MAIN ---
+if __name__ == '__main__':
+    main()