Solve 2019 day 13

2019/d9.py

@@ -9,6 +9,7 @@ class Amp:
         self.inputs = []
         self.outputs = []
         self.done = False
+        self.input_required = False
         self.rel_base = 0
 
     def feed(self, input):
@@ -72,7 +73,10 @@ class Amp:
                     i += 4
                 case 3:
                     # read input
-                    assert len(self.inputs) > 0
+                    if len(self.inputs) == 0:
+                        self.i = i
+                        self.input_required = True
+                        return
                     addr = self.get_addr(i + 1, mode_p1)
                     xs[addr] = self.inputs[0]
                     self.inputs = self.inputs[1:]