Solved 2024/11 P2

2024/11/11.md

@@ -82,8 +82,6 @@ will you have after blinking 25 times?*
 
 Your puzzle answer was `211306`.
 
-The first half of this puzzle is complete! It provides one gold star: \*
-
 ## \-\-- Part Two \-\-- {#part2}
 
 The Historians sure are taking a long time. To be fair, the infinite
@@ -91,8 +89,14 @@ corridors *are* very large.
 
 *How many stones would you have after blinking a total of 75 times?*
 
-Answer:
+Your puzzle answer was `250783680217283`.
 
-Although it hasn\'t changed, you can still [get your puzzle
+Both parts of this puzzle are complete! They provide two gold stars:
+\*\*
+
+At this point, you should [return to your Advent calendar](/2024) and
+try another puzzle.
+
+If you still want to see it, you can [get your puzzle
 input](11/input).
 

2024/11/solution.py

@@ -6,7 +6,7 @@ sys.path.insert(0, '../../')
 from fred import list2int,get_re,nprint,lprint,loadFile
 start_time = time.time()
 
-input_f = 'test'
+input_f = 'input'
 
 part = 1
 #########################################
@@ -15,94 +15,130 @@ part = 1
 #                                       #
 #########################################
 
-def rule1(number:int):
+# Part 1 was first done using a list and each 
-    if number == 0:
+# number in the input list was converted to ints
-        return 1  
+# then each new list was created and passed through 
-    else:
+# again. 
-        print('Number not 0, why are you here')
+# I also did the Part 1 using deque, but this wasn't
+# any faster at all. 
 
 def rule2(number):
-    # Convert the number to a string
     num_str = str(number)          
-    length = len(num_str)
+    middle = len(num_str) // 2
-    
+    return [int(num_str[:middle]), int(num_str[middle:])]
-    # Calculate the split index
-    middle = length // 2
-
-    # Split the number into two parts
-    left_part = num_str[:middle]
-    right_part = num_str[middle:]
-    #print(left_part,right_part)
-
-    return int(left_part), int(right_part)
 
 def part1(input_f):
     instructions = []
     with open(input_f) as file:
         instructions = list2int(file.readline().strip().split(' '))
+
     new_inst = []
     for x in range(25):
         for idx,inst in enumerate(instructions):
 
-            # Rule 1
             if inst == 0:
                 new_inst.append(1)
             else:
-                # Rule 2
+                if len(list(str(inst))) % 2 == 0:
-                t = list(str(inst))
-                if len(t) % 2 == 0:
                     new_inst += rule2(inst)
                 else:
-                    # Rule 3
                     new_inst.append(instructions[idx] * 2024)
         instructions = new_inst
         new_inst = []
     
-    print(len(instructions)) 
+    return len(instructions) 
+
+
+def part1_dq(input_f):
+    dq = []
+    with open(input_f) as file:
+        dq = deque(file.readline().strip().split(' '))
+
+    new_inst = deque([])
+    for r in range(25):
+        i = 0
+        while_time = time.time()
+
+        while i < len(dq):
+            if dq[i] == 0:
+                new_inst.append(1)
+            else:
+                if len(str(dq[i])) % 2 == 0:
+                    x = rule2(dq[i])
+                    new_inst.append(x[0])
+                    new_inst.append(x[1])
+                else:
+                    new_inst.append(int(dq[i]) * 2024)
+            i += 1
+        dq = new_inst
+        new_inst = deque([])
+    return len(dq) 
 
 start_time = time.time()
-part1(input_f)
+print('Part 1:',part1(input_f), '\t\t\t(list)\t', round((time.time() - start_time)*1000), 'ms')
-print("--- %s seconds ---" % (time.time() - start_time))
+start_time = time.time()
+print('Part 1:',part1(input_f), '\t\t\t(deque)\t', round((time.time() - start_time)*1000), 'ms')
+
 #########################################
 #                                       #
 #              Part 2                   #
 #                                       #
 #########################################
 
+# Part 2 was not possible using either list or deque.
+# I tested various calculations to see if there was a 
+# pattern but i couldn't find one. 
+# I started using simple recursion in hopes that 
+# would speed it up. That was not the case.
+# I ended up splitting the function in two and the part
+# that returns a value from the rules, would be stored
+# in a dict where the number and the current blink count 
+# would be the key.
+# If a number+blink combo was already in the dict, it 
+# would use the already calculated result, instead
+# of calculating it again. 
+# I tested using functools.cache on the rules() function
+# but that gave the same compute time.
+
+def rule2(number):
+    num_str = str(number)          
+    middle = len(num_str) // 2
+    return [str(int(num_str[:middle])), str(int(num_str[middle:]))]
+
+def genNewNumbers(start,end):
+    if end == 0:
+        return 1
+    end -= 1
+    if (start,end) not in values:
+        values[(start,end)] = rules(start,end)
+    result = values[(start,end)]
+    return result
+
+def rules(start,end):
+    if start == '0':
+        result = genNewNumbers('1',end) 
+    else:
+        if len(start) % 2 == 0:
+            x = rule2(start)
+            result = 0
+            result += genNewNumbers(x[0],end) 
+            result += genNewNumbers(x[1],end)
+
+        else:
+            result = genNewNumbers(str(int(start)*2024),end)
+    return result
+
+values = {}
+
 def part2(input_f):
-    dq = []
+    numbers = []
     with open(input_f) as file:
-        dq = deque(file.readline().strip().split(' '))
+        numbers = file.readline().strip().split(' ')
-    new_inst = deque([])
 
-    for r in range(75):
+    result = 0
-        i = 0
+    for i in numbers:
-        while_time = time.time()
+        result += genNewNumbers(i,75)
-
+    return result
-        while i < len(dq):
-            if dq[i] == 0:
-                # Rule 1
-                new_inst.append(1)
-            else:
-                # Rule 2
-                if len(str(dq[i])) % 2 == 0:
-
-                    x = rule2(dq[i])
-                    new_inst.append(x[0])
-                    new_inst.append(x[1])
-                    
-                else:
-                    # Rule 3
-                    new_inst.append(int(dq[i]) * 2024)
-            i += 1
- 
-        dq = new_inst
-        new_inst = deque([])
-        print(r,len(dq),"--- %s seconds ---" % (time.time() - while_time))
-
-        #print()
-    print(len(dq)) 
 
 start_time = time.time()
-part2(input_f)
+print('Part 2:',part2(input_f), '\t(cache)\t', round((time.time() - start_time)*1000), 'ms')
-print("--- %s seconds ---" % (time.time() - start_time))

README.md

@@ -12,6 +12,7 @@
     |~~..--. _____  |        |* /~\ '.|    | - /  .'|   8 **
     '---'  ||[][]_\-|        |~/ * \ :|    |  *..'  |   9 **
            |------- |        |   /\ .'|    |'''~~~~~|  10 **
+           |.......||        |/\ ..'  |    |   .    |  11 **
 
 ## 2023