Sum of the digits of n is substring of n: Difference between revisions

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@@ Line 207: / Line 207: @@
 from functools import reduce
+from itertools import chain
@@ Line 223: / Line 224: @@
 def main():
     '''Matches in [0..999]'''
+    print(
-    limit = 1000
+        showMatches(
+            digitSumIsSubString
-    xs = list(
-        filter(
+        )(999)
-            digitSumIsSubString,
-            (str(n) for n in range(0, limit))
-        )
     )
-    w = len(xs[-1])
-    print(f'{len(xs)} matches < {limit}:\n')
+# ----------------------- DISPLAY ------------------------
-    print(
-        '\n'.join(
+# showMatches :: (String -> Bool) -> Int -> String
-            ' '.join(cell.rjust(w, ' ') for cell in row)
+def showMatches(p):
-            for row in chunksOf(10)(xs)
+    '''A listing of the integer strings [0..limit]
+       which match the predicate p.
+    '''
+    def go(limit):
+        def triage(n):
+            s = str(n)
+            return [s] if p(s) else []
+        xs = list(
+            chain.from_iterable(
+                map(triage, range(0, 1 + limit))
+            )
         )
-    )
+        w = len(xs[-1])
+        return f'{len(xs)} matches < {limit}:\n' + (
+            '\n'.join(
+                ' '.join(cell.rjust(w, ' ') for cell in row)
+                for row in chunksOf(10)(xs)
+            )
+        )
+    return go