@[Lenlynn](/user/832997) cout精度默认保留六位有效数字，大数精度不够，寄。
要用cout可以这么写：
```cpp
cout<<fixed<<setprecision(2)<<ans<<endl;
```
by Ja50nY0un9_as_AgNO3 @ 2022-11-16 19:38:43
@[Lenlynn](/user/832997) 精度问题，你试试 `cout << fixed << setprecision(2) << ...`
by Error_Yuan @ 2022-11-16 19:40:02
@[Ja50nY0un9](/user/363302) 了解了，谢谢
by Lenlynn @ 2022-11-16 19:42:00
@[Error_Yuan](/user/358748) 了解了，谢谢
by Lenlynn @ 2022-11-16 19:42:16