✨ feat(eular_12.py)：优化质数测试参数并修复组合数计算逻辑

✨ feat(eular_13.py)：新增超大整数加法解决方案
📝 docs(eular_13.md)：添加算法说明文档
✨ feat(eular_14.py)：新增Collatz序列最长链计算
📝 docs(eular_14.md)：添加性能优化说明
✨ feat(eular_15.py)：新增网格路径组合数学解法
📝 docs(eular_15.md)：添加组合数学详细说明
✨ feat(eular_16.py)：新增幂数字和计算功能
✨ feat(eular_16.hs)：新增Haskell版本实现

solutions/0015.gridpath/eular_15.py

@@ -0,0 +1,21 @@
+"""
+Starting in the top left corner of a 2 X 2 grid,
+and only being able to move to the right and down,
+there are exactly 6 routes to the bottom right corner.
+
+How many such routes are there through a 20 X 20 grid?
+"""
+
+import math
+
+
+def grid_paths(m: int, n: int) -> int:
+    return math.comb(m + n, m)
+
+
+def main() -> None:
+    print(grid_paths(20, 20))
+
+
+if __name__ == "__main__":
+    main()