Add Python solution to challenge 035

2 files changed, 94 insertions, 0 deletions

diff --git a/challenge-035/paulo-custodio/python/ch-1.py b/challenge-035/paulo-custodio/python/ch-1.py
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+++ b/challenge-035/paulo-custodio/python/ch-1.py
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+#!/usr/bin/python3
+
+# Challenge 035
+#
+# TASK #1
+# Contributed by Paul Johnson
+# Write a program to encode text into binary encoded morse code.
+# Pay attention to any changes which might need to be made to the text to
+# make it valid morse code.
+#
+# Morse code consists of dots, dashes and gaps. It can be encoded in binary
+# in the following fashion:
+#
+# dot: 1
+# dash: 111
+# intra-character gap: 0
+# character gap: 000
+# word gap: 0000000
+# An intra-character gap is inserted between the dots and dashes in a character.
+
+import sys
+import re
+
+# morse code chart
+MORSE = { 'A':'.-',    'B':'-...',  'C':'-.-.',  'D':'-..',   'E':'.',
+          'F':'..-.',  'G':'--.',   'H':'....',  'I':'..',    'J':'.---',
+          'K':'-.-',   'L':'.-..',  'M':'--',    'N':'-.',    'O':'---',
+          'P':'.--.',  'Q':'--.-',  'R':'.-.',   'S':'...',   'T':'-',
+          'U':'..-',   'V':'...-',  'W':'.--',   'X':'-..-',  'Y':'-.--',
+          'Z':'--..',  '1':'.----', '2':'..---', '3':'...--', '4':'....-',
+          '5':'.....', '6':'-....', '7':'--...', '8':'---..', '9':'----.',
+          '0':'-----'}
+
+def encode_bin_morse(text):
+    encoded = ""
+    for c in text.upper():
+        if c.isalnum():
+            morse = MORSE[c]
+            morse = re.sub(r"\.", "10", morse)
+            morse = re.sub(r"\-", "1110", morse)
+            encoded += morse+"00"
+        else:
+            encoded += "0000"
+    encoded = re.sub(r"0+$", "", encoded)
+    return encoded
+
+print(encode_bin_morse(" ".join(sys.argv[1:])))
diff --git a/challenge-035/paulo-custodio/python/ch-2.py b/challenge-035/paulo-custodio/python/ch-2.py
new file mode 100644
index 0000000000..f38b35a5bb
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+++ b/challenge-035/paulo-custodio/python/ch-2.py
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+#!/usr/bin/python3
+
+# Challenge 035
+#
+# Challenge 035
+#
+# TASK #2
+# Contributed by Paul Johnson
+# Write a program to decode binary morse code.
+# Consider how it might be possible to recover from badly formed morse code.
+#
+# a) by splitting the morse code on gaps
+# b) without looking further than one digit ahead
+
+import sys
+import re
+
+# morse code chart
+MORSE = { 'A':'.-',    'B':'-...',  'C':'-.-.',  'D':'-..',   'E':'.',
+          'F':'..-.',  'G':'--.',   'H':'....',  'I':'..',    'J':'.---',
+          'K':'-.-',   'L':'.-..',  'M':'--',    'N':'-.',    'O':'---',
+          'P':'.--.',  'Q':'--.-',  'R':'.-.',   'S':'...',   'T':'-',
+          'U':'..-',   'V':'...-',  'W':'.--',   'X':'-..-',  'Y':'-.--',
+          'Z':'--..',  '1':'.----', '2':'..---', '3':'...--', '4':'....-',
+          '5':'.....', '6':'-....', '7':'--...', '8':'---..', '9':'----.',
+          '0':'-----'}
+
+MORSE_INV = {v:k for k, v in MORSE.items()}
+
+def decode_bin_morse(encoded):
+    encoded = re.sub(r"0+$", "", encoded)           # remove trailing 0s
+    encoded = re.sub(r"0000000", "\n", encoded)     # word gap
+    encoded = re.sub(r"000", " ", encoded)          # character gap
+    encoded = re.sub(r"1110?", "-", encoded)        # -
+    encoded = re.sub(r"10?", ".", encoded)          # .
+
+    text = ""
+    words = encoded.split("\n")
+    for word in words:
+        chars = word.split()
+        for c in chars:
+            text += MORSE_INV[c]
+        text += " "
+    text = re.sub(r"\s+$", "", text)
+    return text
+
+print(decode_bin_morse(" ".join(sys.argv[1:])))