Revert "Restructure {reasoning_gym, tests}/{core, exercises, curricula}"

This reverts commit 10dbb374b0.

reasoning_gym/arithmetic/gcd.py

@@ -0,0 +1,66 @@
+"""Greatest Common Divisor (GCD) task generator"""
+
+from dataclasses import dataclass
+from functools import reduce
+from math import gcd
+from random import Random
+from typing import List, Optional, Tuple
+
+from ..factory import ProceduralDataset, register_dataset
+
+
+@dataclass
+class GCDConfig:
+    """Configuration for GCD task generation"""
+
+    min_numbers: int = 2  # Minimum numbers to find GCD of
+    max_numbers: int = 2  # Maximum numbers to find GCD of
+    min_value: int = 1  # Minimum value for each number
+    max_value: int = 1000  # Maximum value for each number
+    seed: Optional[int] = None
+    size: int = 500  # Virtual dataset size
+
+    def validate(self) -> None:
+        """Validate configuration parameters"""
+        assert self.min_numbers >= 2, "min_numbers must be at least 2"
+        assert self.max_numbers >= self.min_numbers, "max_numbers must be >= min_numbers"
+        assert self.min_value >= 1, "min_value must be positive"
+        assert self.max_value > self.min_value, "max_value must be > min_value"
+
+
+class GCDDataset(ProceduralDataset):
+    """Generates Greatest Common Divisor (GCD) tasks"""
+
+    def __init__(self, config: GCDConfig):
+        super().__init__(config=config, 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.
+        Will try up to 3 times to find numbers with GCD > 1."""
+
+        # Try up to 3 times to get GCD > 1
+        for _ in range(3):
+            num_count = rng.randint(self.config.min_numbers, self.config.max_numbers)
+            numbers = [rng.randint(self.config.min_value, self.config.max_value) for _ in range(num_count)]
+            result = reduce(gcd, numbers)
+            if result > 1:
+                break
+
+        # Return the last generated numbers, whether they met the criteria or not
+        return numbers, result
+
+    def __getitem__(self, idx: int) -> dict:
+        """Generate a single GCD task"""
+        rng = Random(self.seed + idx)
+
+        numbers, result = self._generate_numbers(rng)
+        numbers_str = ", ".join(str(n) for n in numbers)
+
+        return {
+            "question": f"Find the Greatest Common Divisor (GCD) of these numbers: {numbers_str}",
+            "answer": str(result),
+            "metadata": {"numbers": numbers, "result": result},
+        }
+
+
+register_dataset("gcd", GCDDataset, GCDConfig)