Compilare: main.cpp: In function 'int eval()': main.cpp:43:18: warning: array subscript has type 'char' [-Wchar-subscripts] 43 | coef[lit] -= c; | ^~~ main.cpp:45:18: warning: array subscript has type 'char' [-Wchar-subscripts] 45 | coef[lit] += c; | ^~~ main.cpp:47:1: warning: no return statement in function returning non-void [-Wreturn-type] 47 | } | ^