2 files changed, 51 insertions, 0 deletions
diff --git a/challenge-277/steven-wilson/python/ch-1.py b/challenge-277/steven-wilson/python/ch-1.py
new file mode 100644
index 0000000000..ce88071a6d
--- /dev/null
+++ b/challenge-277/steven-wilson/python/ch-1.py
@@ -0,0 +1,26 @@
+#!/usr/bin/env python3
+
+from collections import Counter
+
+
+def count_common(words1, words2):
+    """ Given  two array of strings, return the count of words that appears in
+    both arrays exactly once.
+
+    >>> count_common(("Perl", "is", "my", "friend"), ("Perl", "and", "Raku", "are", "friend"))
+    2
+    >>> count_common(("Perl", "and", "Python", "are", "very", "similar"), ("Python", "is", "top", "in", "guest", "languages"))
+    1
+    >>> count_common(("Perl", "is", "imperative", "Lisp", "is", "functional"), ("Crystal", "is", "similar", "to", "Ruby"))
+    0
+    """
+    c1 = Counter(words1)
+    c2 = Counter(words2)
+    return len({k for k, v in c1.items() if v == 1} &
+               {k for k, v in c2.items() if v == 1})
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod(verbose=True)
diff --git a/challenge-277/steven-wilson/python/ch-2.py b/challenge-277/steven-wilson/python/ch-2.py
new file mode 100644
index 0000000000..c75bd2bbb0
--- /dev/null
+++ b/challenge-277/steven-wilson/python/ch-2.py
@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+
+from itertools import combinations
+
+
+def strong_pair(*integers):
+    """ Given an array of integers, return the count of all strong pairs in the
+    given array.
+
+        A pair of integers x and y is called strong pair if it satisfies:
+        0 < |x - y| < min(x, y).
+
+    >>> strong_pair(1, 2, 3, 4, 5)
+    4
+    >>> strong_pair(5, 7, 1, 7)
+    1
+    """
+    return len({(x, y) for x, y in combinations(integers, 2)
+        if 0 < abs(x - y) and abs(x - y) < min(x, y)})
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod(verbose=True)