Ch99 (Python): Tasks 1 & 2

7 files changed, 117 insertions, 0 deletions

diff --git a/challenge-099/tyler-wardhaugh/python/ch-1.py b/challenge-099/tyler-wardhaugh/python/ch-1.py
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+++ b/challenge-099/tyler-wardhaugh/python/ch-1.py
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+#!/usr/bin/env python3
+"""Challenge 99, Task 1"""
+
+import sys
+from fnmatch import fnmatch
+
+
+DEFAULT_INPUT = ('abcde', 'a*e')
+
+
+def pattern_match(string, pattern):
+    """Return true if pattern p matches string s, according to glob rules."""
+    return fnmatch(string, pattern)
+
+
+def main(args=None):
+    """Run the task"""
+    if args is None:
+        args = sys.argv[1:]
+
+    s, p = args[0:1] if args else DEFAULT_INPUT
+    if pattern_match(s, p):
+        print(1)
+    else:
+        print(0)
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/challenge-099/tyler-wardhaugh/python/ch-2.py b/challenge-099/tyler-wardhaugh/python/ch-2.py
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+++ b/challenge-099/tyler-wardhaugh/python/ch-2.py
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+#!/usr/bin/env python3
+"""Challenge 99, Task 2"""
+
+import sys
+import numpy as np
+
+
+DEFAULT_INPUT = ('littleit', 'lit')
+
+
+def unique_subsequences(s, t):
+    """Use a dynamic programming algorithm to solve unique subsequences.
+       Source: https://www.geeksforgeeks.org/count-distinct-occurrences-as-a-subsequence/"""
+
+    m = len(t)
+    n = len(s)
+
+    if m > n:
+        return 0
+
+    # NumPy is overkill for this use case, especially since we're not taking
+    # advantage of any high-performance array manipulations, but I wanted to
+    # show its use.
+    dp = np.zeros((m + 1, n + 1), dtype=int)
+    dp[0, :] = np.ones(n + 1)
+
+    with np.nditer(dp, flags=['multi_index'], order='C') as it:
+        while not it.finished:
+            i, j = it.multi_index
+            it.iternext()
+
+            if i == 0 or j == 0:
+                continue
+
+            if t[i - 1] != s[j - 1]:
+                dp[i][j] = dp[i][j - 1]
+            else:
+                dp[i][j] = dp[i][j - 1] + dp[i - 1][j - 1]
+
+    return dp[m][n]
+
+
+def main(args=None):
+    """Run the task"""
+    if args is None:
+        args = sys.argv[1:]
+
+    s, t = args[0:1] if args else DEFAULT_INPUT
+    print(unique_subsequences(s, t))
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/challenge-099/tyler-wardhaugh/python/ch1.py b/challenge-099/tyler-wardhaugh/python/ch1.py
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+++ b/challenge-099/tyler-wardhaugh/python/ch1.py
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+ch-1.py
\ No newline at end of file
diff --git a/challenge-099/tyler-wardhaugh/python/ch2.py b/challenge-099/tyler-wardhaugh/python/ch2.py
new file mode 120000
index 0000000000..13a132b99f
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+++ b/challenge-099/tyler-wardhaugh/python/ch2.py
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+ch-2.py
\ No newline at end of file
diff --git a/challenge-099/tyler-wardhaugh/python/requirements.txt b/challenge-099/tyler-wardhaugh/python/requirements.txt
new file mode 100644
index 0000000000..a39ae54275
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+++ b/challenge-099/tyler-wardhaugh/python/requirements.txt
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+numpy==1.20.1
diff --git a/challenge-099/tyler-wardhaugh/python/test_ch1.py b/challenge-099/tyler-wardhaugh/python/test_ch1.py
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index 0000000000..94e18be7b3
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+++ b/challenge-099/tyler-wardhaugh/python/test_ch1.py
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+#!/usr/bin/env python3
+
+import unittest
+from ch1 import pattern_match
+
+class TestTask1(unittest.TestCase):
+
+
+    def test_example_cases(self):
+        self.assertTrue(pattern_match("abcde", "a*e"))
+        self.assertFalse(pattern_match("abcde", "a*d"))
+        self.assertFalse(pattern_match("abcde", "?b*d"))
+        self.assertTrue(pattern_match("abcde", "a*c?e"))
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/challenge-099/tyler-wardhaugh/python/test_ch2.py b/challenge-099/tyler-wardhaugh/python/test_ch2.py
new file mode 100755
index 0000000000..968a4fe8e4
--- /dev/null
+++ b/challenge-099/tyler-wardhaugh/python/test_ch2.py
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+#!/usr/bin/env python3
+
+import unittest
+from ch2 import unique_subsequences
+
+class TestTask2(unittest.TestCase):
+
+
+    def test_example_cases(self):
+        self.assertEqual(5, unique_subsequences('littleit', 'lit'))
+        self.assertEqual(3, unique_subsequences('london', 'lon'))
+
+
+if __name__ == '__main__':
+    unittest.main()