From 3027b78e882dba0c360b4c1d2b73017131919049 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Doblas=20Jim=C3=A9nez?=
 <david.doblas-jimenez@xfel.eu>
Date: Fri, 6 Aug 2021 16:39:20 +0200
Subject: [PATCH] Module 12: Pattern Hash (Python code only)

---
 a.py | 33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/a.py b/a.py
index 71941df..e783b7b 100644
--- a/a.py
+++ b/a.py
@@ -2,11 +2,16 @@ def ToUpper(s):
     return s.upper()
 
 
+## ----------------------------------------------------------------------------
+##-Words
 class Words:
 
     def __init__(self):
         self.word = []
 
+
+## ----------------------------------------------------------------------------
+##-Library
 class Library:
 
     def __init__(self):
@@ -16,6 +21,10 @@ class Library:
         # hash table
         self.word_map_ = {}
 
+    # Returns NULL if can't find any matches to the given pattern
+    def FindWord(self, s):
+        print(list(key for key, values in self.word_map_.items() if s in values))
+
     def IsWord(self, s):
         return s in self.word_map_
 
@@ -39,12 +48,26 @@ class Library:
         assert (i >= 0 and i < len(self.words_))
         return self.words_[i]
 
+    def CreatePatternHash(self, w):
+        len_w = len(w)
+        num_patterns = 1 << len_w
+#        print(f"PATTERN HASH on {w}")
+        self.word_map_[w] = []
+        for i in range(num_patterns):
+#            print(f"  {i}")
+            tmp = list(w)
+            for j in range(len_w):
+                if ((i >> j) & 1):
+                    tmp[j] = "-"
+#            print(f'  {"".join(tmp)}')
+            self.word_map_[w].append("".join(tmp))
+
     def ReadFromFile(self, filename):
         with open(filename, 'r') as f:
             for line in f:
                 line = ToUpper(line.rstrip())
                 self.words_.word.append(line)
-                self.word_map_[line] = line
+                self.CreatePatternHash(line)
         print(f"Read {len(self.words_.word)} words from file '{filename}'")
 
     def DebugBuckets(self):
@@ -88,14 +111,8 @@ class Grid:
 if __name__ == "__main__":
     lib = Library()
     lib.ReadFromFile("top_12000.txt")
-    # lib.ComputeStats()
-    # lib.PrintStats()
 
-    print(lib.IsWord("DOG"))
-    print(lib.IsWord("CAT"))
-    print(lib.IsWord("THANKS"))
-    print(lib.IsWord("TFAFAS"))
-    lib.DebugBuckets()
+    lib.FindWord("D--")
 
     # grid = Grid("MY GRID")
     # grid.LoadFromFile("test")