commit day 19, 20 and 21

19 and 20 are incomplete and nothing is optimized

20/1.py

@@ -0,0 +1,37 @@
+with open("input") as f:
+    content = [x.strip() for x in f]
+
+def simplify_tile(tile):
+    result = []
+    result.append(tile[0])
+    result.append("".join([x[0] for x in tile]))
+    result.append("".join([x[-1] for x in tile]))
+    result.append(tile[-1])
+    return result
+
+tiles = {}
+new_tile = []
+for c in content:
+    if not c:
+        tiles[tile_id] = simplify_tile(new_tile)
+        new_tile = []
+    elif c.startswith("Tile"):
+        tile_id = int(c[5:-1])
+    else:
+        new_tile.append(c)
+
+def find_match(tiles, tile_id, border):
+    for t_id, tile in tiles.items():
+        if t_id != tile_id:
+            for b in tile:
+                if b == border or b == "".join(list(reversed(border))):
+                    return True
+
+    return False
+
+result = 1
+for tile_id, tile in tiles.items():
+    if list(map(lambda x: find_match(tiles, tile_id, x), tile)).count(True) == 2:
+        result *= tile_id
+
+print(result)