1 files changed, 49 insertions, 0 deletions
diff --git a/23/solution.py b/23/solution.py
new file mode 100644
index 0000000..00144bf
--- /dev/null
+++ b/23/solution.py
@@ -0,0 +1,49 @@
+def run(instructions, a=0, b=0):
+    ip = 0
+    regs = {
+        'a': a,
+        'b': b,
+    }
+
+    def set(r, v):
+        regs[r] = v
+        return 1
+
+    act = {
+        'hlf': lambda r: set(r, regs[r] // 2),
+        'tpl': lambda r: set(r, regs[r] * 3),
+        'inc': lambda r: set(r, regs[r] + 1),
+        'jmp': lambda offset: offset,
+        'jie': lambda r, offset: offset if regs[r] % 2 == 0 else 1,
+        'jio': lambda r, offset: offset if regs[r] == 1 else 1,
+    }
+
+    while 0 <= ip < len(instructions):
+        ins, ops = instructions[ip]
+        ip += act[ins](*ops)
+        # print(f'ins={ins}, ops={ops}, a={regs["a"]}, b={regs["b"]}, ip={ip}')
+
+    return regs
+
+def part1(instructions):
+    return run(instructions)['b']
+
+def part2(instructons):
+    return run(instructions, 1)['b']
+
+if __name__ == '__main__':
+    with open('input') as f:
+        instructions = list()
+        for line in f:
+            line = line.rstrip()
+            opcode, operands = line.split(' ', maxsplit=1)
+            def parse_operand(s: str) -> int | str:
+                if s[0] == '+':
+                    return int(s[1:])
+                elif s[0] == '-':
+                    return -int(s[1:])
+                return s
+            operands = tuple(parse_operand(op) for op in operands.split(', '))
+            instructions.append((opcode, operands))
+    print(part1(instructions))
+    print(part2(instructions))