Rewriting control work 1

src/rewriting_hw_1/walker_scheme.py

@@ -0,0 +1,76 @@
+from math import floor
+
+
+class WalkerScheme:
+    def __init__(self, events_and_probabilities: list[tuple[str, int]]):
+        if sum(probability[1] for probability in events_and_probabilities) != 1:
+            raise Exception("Сумма вероятностей не равна 1.")
+        self.table = self._get_table(events_and_probabilities)
+
+    def _get_table(self, events_and_probabilities):
+        """Генерирует таблицу Уолкера."""
+        equal_probability = (
+            1 / len(events_and_probabilities)
+        )  # Переменная с вероятностью события, если бы все события были равновероятными.
+        probabilities = {
+            event: equal_probability for event, _ in events_and_probabilities
+        }  # Словарь, где изначально все вероятности эквивалентны и меняются после донорства кого-то кому-то.
+        how_many_added_for_event = {
+            event: 0 for event, _ in events_and_probabilities
+        }  # Для заполнения нерозданных отрезков в конце
+        table = []
+        global_barrier = 0
+
+        for i in range(len(events_and_probabilities)):
+            break_flag = False
+            for donor_event, donor_probability in events_and_probabilities:
+                if donor_probability < probabilities[donor_event]:
+                    for (
+                        recipient_event,
+                        recipient_probability,
+                    ) in events_and_probabilities:
+                        if recipient_probability > probabilities[recipient_event]:
+                            table.append(
+                                (
+                                    donor_event,
+                                    recipient_event,
+                                    global_barrier
+                                    + equal_probability
+                                    - probabilities[donor_event]
+                                    + donor_probability,  # Подсчёт барьера, где к глобальному барьеру прибавляется остаток вероятности донора по модулю эквивалентной вероятности
+                                )
+                            )
+                            global_barrier += equal_probability
+
+                            how_many_added_for_event[recipient_event] += (
+                                equal_probability
+                                - probabilities[donor_event]
+                                + donor_probability
+                            )
+                            how_many_added_for_event[donor_event] += (
+                                probabilities[donor_event] - donor_probability
+                            )
+
+                            probabilities[recipient_event] += (
+                                probabilities[donor_event] - donor_probability
+                            )
+                            probabilities[donor_event] = donor_probability
+
+                            break_flag = True
+                            break
+                    if break_flag:
+                        break
+            else:  # Для оставшихся
+                for event, probability in how_many_added_for_event.items():
+                    print(how_many_added_for_event)
+                    if probability < probabilities[event]:
+                        global_barrier += equal_probability
+                        table.append((event, event, global_barrier))
+                        break
+
+        return table
+
+    def get_random(self, probability):
+        if self.table[floor(probability * len(self.table))][2] > probability:
+            return self.table[floor(probability * len(self.table))][0]
+        return self.table[floor(probability * len(self.table))][1]

tests/walker_scheme_test.py

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+from rewriting_hw_1.walker_scheme import WalkerScheme
+
+
+def test_exception():
+    try:
+        scheme = WalkerScheme([("A", 0.1), ("B", 1)])
+        print(scheme)
+    except Exception as e:
+        assert str(e) == "Сумма вероятностей не равна 1."