Kayode-week9. Longest Common Subsequence

week9/longest_common_subsequence.PY

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+from itertools import combinations
+
+def LCS(strArr):
+    first= strArr[0]
+    second= strArr[1]
+
+    firstsubs= []
+    secondsubs= []
+    for i in range(len(first)):
+        comb1= list(combinations(first, i))
+        comb2=[]
+        for j in comb1:
+            comb2.append(''.join(j))
+        firstsubs.extend(comb2)
+
+
+    for i in range(len(second)):
+        comb3= list(combinations(second, i))
+        comb4=[]
+        for j in comb3:
+            comb4.append(''.join(j))
+        secondsubs.extend(comb4)
+
+    firstsubs.remove('')
+    secondsubs.remove('')
+    if firstsubs == []:
+        firstsubs.append(first)
+    if secondsubs == []:
+        secondsubs.append(second)
+
+    sublength= 0
+
+    for i in firstsubs:
+        for j in secondsubs:
+            if i == j:
+                if len(i) > sublength:
+                    sublength= len(i)
+
+
+    print(sublength)
+
+
+
+# LCS(['bcacb', 'aacabb'])
+LCS(['a', 'aa'])
+# LCS(['c', 'b'])

week9/longest_common_subsequence.md

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+---
+Author: Kayode
+---
+
+Longest Common Subsequence (LCS)
+Have the function LCS(strArr) take the strArr parameter being passed which will be an array of two strings containing only the characters {a,b,c} and have your program return the length of the longest common subsequence common to both strings. A common subsequence for two strings does not require each character to occupy consecutive positions within the original strings. For example: if strArr is ["abcabb","bacb"] then your program should return 3 because one longest common subsequence for these two strings is "bab" and there are also other 3-length subsequences such as "acb" and "bcb" but 3 is the longest common subsequence for these two strings.
+
+
+Examples
+Input: ["abc","cb"]
+Output: 1
+
+Input: ["bcacb","aacabb"
+Output: 3