Change the dir structure slightly

interview_problems/longest_common_prefix.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+def longest_common_substring(s1, s2):
+    p1 = 0
+    aux, lcp = '', ''
+    string1 = max(s1, s2)
+    string2 = min(s1, s2)
+
+    while p1 < len(string1):
+        p2 = 0
+        while  p2 < len(string2) and p1+p2 < len(string1):
+            if string1[p1+p2] == string2[p2]:
+                aux += string1[p1+p2]
+            else:
+                if len(lcp) < len(aux):
+                    lcp = aux
+                aux = ''
+            p2 += 1
+        p1 += 1
+
+    return lcp
+             
+    
+    
+if __name__ == '__main__':
+    str1 = 'hasfgeaae'
+    str2 = 'bafgekk'
+    result = 'fge'
+    assert(longest_common_substring(str1, str2) == result)