Longest subsequence done! (3 seqs)

The only tricky part was to create and populate the 3-d list. The
instructions here was helpful:
https://www.ict.social/python/basics/multidimensional-lists-in-python

2 files changed, 72 insertions, 0 deletions

diff --git a/AlgoDesignAndTechniqueEdxPython/sources/lcs3.py b/AlgoDesignAndTechniqueEdxPython/sources/lcs3.py
new file mode 100644
index 0000000..4de6a44
--- /dev/null
+++ b/AlgoDesignAndTechniqueEdxPython/sources/lcs3.py
@@ -0,0 +1,44 @@
+#Uses python3
+
+import sys
+def getLCS3(a, b, c):
+    l = len(c)
+    m = len(b)
+    n = len(a)
+# https://www.ict.social/python/basics/multidimensional-lists-in-python
+# The link above provides good tutorial for creating the 3-d list.
+    D = []
+    for _ in range(n + 1):
+        x = []
+        for _ in range(m + 1):
+            y = []
+            for _ in range(l + 1):
+                y.append(0)
+            x.append(y)
+        D.append(x)
+    
+    for k in range(1, l + 1):
+        for j in range(1, m + 1):
+            for i in range(1, n + 1):
+                if a[i - 1] == b[j - 1] == c[k - 1]:
+                    D[i][j][k] = D[i - 1][j - 1][k - 1] + 1
+                else:
+                    D[i][j][k] = max(D[i - 1][j][k], D[i][j - 1][k], D[i][j][k - 1])
+
+    return D[n][m][l]
+
+if __name__ == '__main__':
+    input = sys.stdin.read()
+    data = list(map(int, input.split()))
+    an = data[0]
+    data = data[1:]
+    a = data[:an]
+    data = data[an:]
+    bn = data[0]
+    data = data[1:]
+    b = data[:bn]
+    data = data[bn:]
+    cn = data[0]
+    data = data[1:]
+    c = data[:cn]
+    print(getLCS3(a, b, c))
\ No newline at end of file
diff --git a/AlgoDesignAndTechniqueEdxPython/tests/lcs3Test.py b/AlgoDesignAndTechniqueEdxPython/tests/lcs3Test.py
new file mode 100644
index 0000000..c5cf51e
--- /dev/null
+++ b/AlgoDesignAndTechniqueEdxPython/tests/lcs3Test.py
@@ -0,0 +1,28 @@
+'''
+Created on Dec 25, 2018
+
+@author: haidong
+'''
+import unittest
+
+from sources.lcs3 import getLCS3
+
+
+class Test(unittest.TestCase):
+
+    def testName(self):
+        a = [1, 2, 3]
+        b = [2, 1, 3]
+        c = [1, 3, 5]
+        self.assertEqual(2, getLCS3(a, b, c))
+
+    def testName1(self):
+        a = [8, 3, 2, 1, 7]
+        b = [8, 2, 1, 3, 8, 10, 7]
+        c = [6, 8, 3, 1, 4, 7]
+        self.assertEqual(3, getLCS3(a, b, c))
+
+
+if __name__ == "__main__":
+    # import sys;sys.argv = ['', 'Test.testName']
+    unittest.main()