Solve 2018 day 19 finally

2018/d19.py

@@ -2,40 +2,133 @@ from lib import get_data, str_to_ints
 import d16
 
 
-def part_1(data):
+def print_regs(regs):
+    print(" ".join([f"regs[{i}]={regs[i]:10}" for i in range(len(regs))]) + " (ip)")
+
+
+def print_inst(i, insts, ip):
+    op, arg1, arg2, dest = insts[i]
+    dest = f"regs[{dest}]" if dest != ip else "ip"
+    match op:
+        case "addi":
+            print(f"{i:2} {dest} = regs[{arg1}] + {arg2}")
+        case "addr":
+            print(f"{i:2} {dest} = regs[{arg1}] + regs[{arg2}]")
+        case "muli":
+            print(f"{i:2} {dest} = regs[{arg1}] * {arg2}")
+        case "mulr":
+            print(f"{i:2} {dest} = regs[{arg1}] * regs[{arg2}]")
+        case "seti":
+            print(f"{i:2} {dest} = {arg1}")
+        case "setr":
+            print(f"{i:2} {dest} = regs[{arg1}]")
+        case "eqrr":
+            print(f"{i:2} {dest} = (regs[{arg1}] == regs[{arg2}]) ? 1 : 0")
+        case "gtrr":
+            print(f"{i:2} {dest} = (regs[{arg1}] > regs[{arg2}]) ? 1 : 0")
+        case _:
+            print(f"{i:2} {dest} = {op}({arg1}, {arg2})")
+
+
+def sum_of_divisors(n):
+    total = 1
+    for i in range(2, int(n**0.5) + 1):
+        if n % i == 0:
+            total += i
+            if i != n // i:  # do not count square root twice
+                total += n // i
+    if n != 1:
+        total += n
+    return total
+
+
+def run(data, break_after=None, reg_zero_init=0):
     ip = None
     regs = [0 for _ in range(6)]
-
-    regs[0] = 1  # part 2
+    regs[0] = reg_zero_init
 
     insts = []
     for line in data.splitlines():
         if line.startswith("#"):
-            ip, = str_to_ints(line)
+            (ip,) = str_to_ints(line)
         else:
             fs = line.split()
             vals = str_to_ints(line)
             insts.append([fs[0]] + vals)
 
+    count = 0
     assert ip is not None
     while regs[ip] < len(insts):
+        if break_after is not None and count > break_after:
+            break
         inst = insts[regs[ip]]
         f = getattr(d16, inst[0])
-        # if inst[1:] == [3, 1, 3]:
-        #     regs[3] = regs[1]
-        #     regs[4] = regs[1]
         f(regs, *inst[1:])
         regs[ip] += 1
-        print(regs, regs[-1] + 1)
+        count += 1
+    return regs
+
+
+def part_1(data):
+    regs = run(data)
     print(regs[0])
 
 
+def part_2(data):
+    regs = run(data, 10_000, 1)
+    # by analysing the code we can see that the int computer counts the sum of
+    # the number of divisors
+    print(sum_of_divisors(regs[1]))
 
 
 def main():
     data = get_data(__file__)
     part_1(data)
+    part_2(data)
 
 
 if __name__ == "__main__":
     main()
+
+
+listing = """
+ip=5
+ 0 ip = regs[5] + 16
+ 1 regs[2] = 1
+ 2 regs[4] = 1
+ 3 regs[3] = regs[2] * regs[4]              |
+ 4 regs[3] = (regs[3] == regs[1]) ? 1 : 0   |
+ 5 ip = regs[3] + regs[5]                   | jump to 7 if regs[3] == regs[1]
+ 6 ip = regs[5] + 1                         | skip 7
+ 7 regs[0] = regs[2] + regs[0]
+ 8 regs[4] = regs[4] + 1                    | regs[4] += 1
+ 9 regs[3] = (regs[4] > regs[1]) ? 1 : 0    |
+10 ip = regs[5] + regs[3]                   | jump to 12 if regs[4] > regs[1]
+11 ip = 2                                   | goto 3
+12 regs[2] = regs[2] + 1                    | regs[2] += 1
+13 regs[3] = (regs[2] > regs[1]) ? 1 : 0    | 
+14 ip = regs[3] + regs[5]                   | jump to 16 if regs[2] > regs[1]
+15 ip = 1                                   | goto 2
+16 ip = regs[5] * regs[5]
+17 regs[1] = regs[1] + 2
+18 regs[1] = regs[1] * regs[1]
+19 regs[1] = regs[5] * regs[1]
+20 regs[1] = regs[1] * 11
+21 regs[3] = regs[3] + 6
+22 regs[3] = regs[3] * regs[5]
+23 regs[3] = regs[3] + 15
+24 regs[1] = regs[1] + regs[3]
+25 ip = regs[5] + regs[0]
+26 ip = 0
+27 regs[3] = regs[5]
+28 regs[3] = regs[3] * regs[5]
+29 regs[3] = regs[5] + regs[3]
+30 regs[3] = regs[5] * regs[3]
+31 regs[3] = regs[3] * 14
+32 regs[3] = regs[3] * regs[5]
+33 regs[1] = regs[1] + regs[3]
+34 regs[0] = 0
+35 ip = 0
+
+hypothesis: usm of numbers that divide the number in regs[0]
+"""

README.md

@@ -106,7 +106,9 @@ Solutions and utility script for Advent of Code challenges in Python.
 - Day 16: 36:10
 - Day 17: 180:00
 - Day 18: 24:04
-- Day 19: 
+- Day 19: days, super fun, but hard for me
+- Day 20:
+- Day 21:
 
 ## AoC 2019