If any like me get this error while importing the Pbds in #includes..
I got error importing this -> #include<ext/pb_ds/assoc_container.hpp> Error was "cannot open source file hash_standard_resize_policy_imp.hpp ".
Fix go to the dir -> C:\MinGW\lib\gcc\mingw32\8.2.0\include\c++\ext\pb_ds\detail\resize_policy
There u will see a file similar to -> "hash_standard_resize_policy_imp.hpp0000644"
Rename it to hash_standard_resize_policy_imp.hpp
and now it worked for me .
I don't know the real reason why the file was weirdly name before if someone knows plz comment down below and tell.
Hope this helps.