If some problem has a source file a.cpp and a solution a.cpp then:
$ polygon-cli init ...
$ polygon-cli update
Invoking problem.files 200
Invoking problem.solutions 200
Downloading new file a.cpp to src/a.cpp
Invoking problem.viewFile 200
...
Updating local file a from a.cpp
Invoking problem.viewSolution 200
...
| solution | a.cpp | src/a.cpp | Not changed |