Day 04: Solution of part 2

unstko · unstko · commit 66370970e3d3 · 2016-12-14T18:46:07.000+01:00
diff --git a/04/log.txt b/04/log.txt
@@ -16,8 +16,6 @@ What is the sum of the sector IDs of the real rooms?
 
 Your puzzle answer was 409147.
 
-The first half of this puzzle is complete! It provides one gold star: *
-
 --- Part Two ---
 
 With all the decoy data out of the way, it's time to decrypt this list and get moving.
@@ -28,4 +26,8 @@ To decrypt a room name, rotate each letter forward through the alphabet a number
 
 For example, the real name for qzmt-zixmtkozy-ivhz-343 is very encrypted name.
 
-What is the sector ID of the room where North Pole objects are stored?
+What is the sector ID of the room where North Pole objects are stored?
+
+Your puzzle answer was 991.
+
+Both parts of this puzzle are complete! They provide two gold stars: **
diff --git a/04/solution.py b/04/solution.py
@@ -7,32 +7,47 @@
 class Solution(solution.Solution):
     def __init__(self, nr):
         super().__init__(nr)
-        self.sum1 = 0
+        self.params["room name"] = "northpole object storage"
+        self.sum = 0
 
     def calculate(self, test=False):
         self.read_instructions()
-        self.calc_part1()
+        self.process_room_list()
 
     def read_instructions(self):
         self.read_input(True)
 
-    def calc_part1(self):
+    def process_room_list(self):
         for line in self.input:
             match = re.match('([a-z\-]+)-(\d+)\[([a-z]{5})\]', line)
             if match:
                 name = match.group(1)
-                sector_id = match.group(2)
+                sector_id = int(match.group(2))
                 checksum = match.group(3)
                 if self.get_checksum(name) == checksum:
-                    self.sum1 += int(sector_id)
-        self.set_solution(1, self.sum1)
+                    self.sum += sector_id
+                    name_decrypted = self.decrypt_name(name, sector_id)
+                    # print(name_decrypt)
+                    if name_decrypted == self.params["room name"]:
+                        self.set_solution(2, sector_id)
+        self.set_solution(1, self.sum)
 
     @staticmethod
-    def get_checksum(name):
+    def get_checksum(string):
         d = collections.defaultdict(int)
-        for c in name:
+        for c in string:
             if c.isalpha():
                 d[c] -= 1
         s = collections.OrderedDict(sorted(d.items(), key=operator.itemgetter(1, 0)))
         checksum = "".join(str(x) for x in s)[:5]
         return checksum
+
+    @staticmethod
+    def decrypt_name(name, shift):
+        decrypted = ""
+        for c in name:
+            if c.isalpha():
+                decrypted += chr((ord(c.lower()) - 97 + shift) % 26 + 97)
+            if c == "-":
+                decrypted += " "
+        return decrypted
diff --git a/04/test.py b/04/test.py
@@ -15,3 +15,9 @@ def test_1(self):
         """
         self.execute_test(test_input)
         self.assertEqual(1514, self.solution.get_solution(1))
+
+    def test_2(self):
+        test_input = """qzmt-zixmtkozy-ivhz-343[zimth]"""
+        self.set_param("room name", "very encrypted name")
+        self.execute_test(test_input)
+        self.assertEqual(343, self.get_solution(2))
