refactor: Inherit GCDDataset from ProceduralDataset base class

reasoning_gym/arithmetic/gcd.py

@@ -2,6 +2,7 @@
 from dataclasses import dataclass
 from random import Random
 from typing import List, Optional, Tuple
+from ..dataset import ProceduralDataset
 from math import gcd
 from functools import reduce
 
@@ -24,27 +25,13 @@ class GCDConfig:
         assert self.max_value > self.min_value, "max_value must be > min_value"
 
 
-class GCDDataset:
+class GCDDataset(ProceduralDataset):
     """Generates Greatest Common Divisor (GCD) tasks"""
 
     def __init__(self, config: GCDConfig):
         self.config = config
         self.config.validate()
-        self.seed = config.seed if config.seed is not None else Random().randint(0, 2**32)
-
-    def __len__(self) -> int:
-        return self.config.size
-
-    def __iter__(self):
-        self._current_idx = 0
-        return self
-
-    def __next__(self):
-        if self._current_idx >= self.config.size:
-            raise StopIteration
-        item = self[self._current_idx]
-        self._current_idx += 1
-        return item
+        super().__init__(seed=config.seed, size=config.size)
 
     def _generate_numbers(self, rng: Random) -> Tuple[List[int], int]:
         """Generate a list of random positive integers and their GCD.