Challenge 283 solutions by Packy Anderson

  * Raku that maybe looks like Raku, but mostly like Perl
  * Perl
  * Python that definitely looks like Perl
  * Elixir

1 Blog post

1 files changed, 45 insertions, 0 deletions

diff --git a/challenge-283/packy-anderson/python/ch-1.py b/challenge-283/packy-anderson/python/ch-1.py
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+#!/usr/bin/env python
+
+from collections import Counter
+
+def uniqueNumber(ints):
+  bag = Counter(ints)  # count occurrences
+  keys = [
+    k                      # return just the keys
+    for k,v in bag.items() # get key/value pairs
+    if v == 1              # keys that occur once
+  ]
+
+  # invalid input
+  if len(keys) == 0:
+    return 'no element appears only once'
+  if len(keys) > 1:
+    return 'multiple elements appear only once'
+
+  # return the one value
+  return keys.pop(0)
+
+def comma_join(arr):
+    return ', '.join(map(lambda i: str(i), arr))
+
+def solution(ints):
+    print(f'Input: @ints = ({comma_join(ints)})')
+    print(f'Output: {uniqueNumber(ints)}')
+
+print('Example 1:')
+solution([3, 3, 1])
+
+print('\nExample 2:')
+solution([3, 2, 4, 2, 4])
+
+print('\nExample 3:')
+solution([1])
+
+print('\nExample 4:')
+solution([4, 3, 1, 1, 1, 4])
+
+print('\nInvalid Input 1 (no element appears only once):')
+solution([4, 1, 1, 1, 4])
+
+print('\nInvalid Input 2 (multiple elements appear only once):')
+solution([1, 2, 3, 4])