Merge remote-tracking branch 'upstream/master'

1 files changed, 45 insertions, 0 deletions

diff --git a/challenge-190/sgreen/python/ch-2.py b/challenge-190/sgreen/python/ch-2.py
new file mode 100755
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+++ b/challenge-190/sgreen/python/ch-2.py
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+#!/usr/bin/env python3
+
+import string
+import sys
+
+
+def main(s):
+    '''Main function'''
+
+    # Loop through the alphabet
+    letter_map = {}
+    for k, v in enumerate(string.ascii_uppercase):
+        letter_map[str(k+1)] = v
+
+    # Record completed solutions
+    solutions = []
+
+    # Start with the input string
+    stack = [(s, '')]
+
+    while stack:
+        (numbers, letters) = stack.pop(0)
+
+        if numbers == '':
+            # If we have no numbers for this stack, it is a solution
+            solutions.append(letters)
+        else:
+            # Consider either the first single or two numbers
+            for l in (1, 2):
+                if len(numbers) >= l and numbers[:l] in letter_map:
+                    # If we have a mapping, add to the stack list with the
+                    #  remaining numbers, and appending this letter to the
+                    #  letters
+                    stack.append(
+                        (numbers[l:], letters + letter_map[numbers[:l]]))
+
+    # Print the solutions
+    if solutions:
+        print(*sorted(solutions), sep=', ')
+    else:
+        print('No solution possible')
+
+
+if __name__ == '__main__':
+    main(sys.argv[1])