Solve 2019 day 23

2019/d22.py

@@ -9,12 +9,12 @@ for line in data.splitlines():
     if "new stack" in line:
         deck = list(reversed(deck))
     elif "cut" in line:
-        n, = str_to_ints(line)
+        (n,) = str_to_ints(line)
         deck = deck[n:] + deck[:n]
     elif "increment" in line:
         new_deck = [-1] * len(deck)
         pos = 0
-        n, = str_to_ints(line)
+        (n,) = str_to_ints(line)
         deck = list(reversed(deck))
         while deck:
             new_deck[pos] = deck.pop()
@@ -37,7 +37,7 @@ for line in data.splitlines():
         assert rev_index == index
         index = new_index
     elif "cut" in line:
-        cut, = str_to_ints(line)
+        (cut,) = str_to_ints(line)
         cut = (len + cut) % len
         if index >= cut:
             new_index = index - cut
@@ -48,7 +48,7 @@ for line in data.splitlines():
         index = new_index
         # calculate index from new_index and store in rev_index
     elif "increment" in line:
-        n, = str_to_ints(line)
+        (n,) = str_to_ints(line)
         assert gcd(n, len) == 1
         new_index = (n * index) % len
         m = mod_inverse(n, len)
@@ -63,11 +63,11 @@ for line in reversed(data.splitlines()):
     if "new stack" in line:
         index = -(index - len + 1)
     elif "cut" in line:
-        cut, = str_to_ints(line)
+        (cut,) = str_to_ints(line)
         cut = (len + cut) % len
         index = (index + cut) % len
     elif "increment" in line:
-        n, = str_to_ints(line)
+        (n,) = str_to_ints(line)
         assert gcd(n, len) == 1
         m = mod_inverse(n, len)
         index = (index * m) % len
@@ -80,6 +80,7 @@ len = 119315717514047
 
 # get expression for one loop using sympy
 from sympy import symbols, simplify
+
 index = symbols("index")
 expr = index
 for line in lines:
@@ -87,16 +88,16 @@ for line in lines:
         # index = -(index - len + 1)
         expr = -(expr - len + 1)
     elif "cut" in line:
-        cut, = str_to_ints(line)
+        (cut,) = str_to_ints(line)
         cut = (len + cut) % len
         # index = (index + cut) % len
-        expr = (expr + cut)
+        expr = expr + cut
     elif "increment" in line:
-        n, = str_to_ints(line)
+        (n,) = str_to_ints(line)
         assert gcd(n, len) == 1
         m = mod_inverse(n, len)
         # index = (index * m) % len
-        expr = (expr * m)
+        expr = expr * m
 
 # we can see that expression is in the form (a - b * i) % m
 expr = simplify(expr % len)
@@ -115,4 +116,3 @@ term1 = (p_t * r0) % m
 term2 = (a * (1 - p_t) * inv_b1) % m
 r_t = (term1 + term2) % m
 print(r_t)
-

2019/d23.py

@@ -0,0 +1,47 @@
+from lib import get_data, str_to_ints
+from d9 import Amp
+
+xs = str_to_ints(get_data(__file__))
+first_255 = True
+nat = None
+y_prev = None
+
+amps = []
+for i in range(50):
+    a = Amp(xs)
+    a.feed(i)
+    a.go()
+    amps.append(a)
+
+for j in range(1_000_000):
+    was_active = False
+    for i, a in enumerate(amps):
+        a.go()
+        if a.input_required:
+            a.feed(-1)
+
+        if len(a.outputs) > 0:
+            was_active = True
+            while len(a.outputs) < 3:
+                a.go()
+            addr = a.pop()
+            x = a.pop()
+            y = a.pop()
+            if addr == 255:
+                nat = (x, y)
+                if first_255:
+                    print(y)
+                    first_255 = False
+            else:
+                amps[addr].feed(x)
+                amps[addr].feed(y)
+
+    if not was_active and nat is not None:
+        x, y = nat
+        if y == y_prev:
+            print(y)
+            exit()
+        amps[0].feed(x)
+        amps[0].feed(y)
+        nat = None
+        y_prev = y