Compilare: main.cpp: In function 'int main()': main.cpp:29:15: warning: array subscript has type 'char' [-Wchar-subscripts] 29 | frecv[ch]++; | ^~ main.cpp:30:18: warning: array subscript has type 'char' [-Wchar-subscripts] 30 | if(frecv[ch] == 1) | ^~ main.cpp:35:19: warning: array subscript has type 'char' [-Wchar-subscripts] 35 | frecv[eliminat]--; | ^~~~~~~~ main.cpp:36:22: warning: array subscript has type 'char' [-Wchar-subscripts] 36 | if(frecv[eliminat] == 0){ | ^~~~~~~~ main.cpp:40:21: warning: comparison of integer expressions of different signedness: 'std::queue<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 40 | if(Q.size() > n_max){ | ~~~~~~~~~^~~~~~~