Compilare: user.cpp: In function ‘void solve()’: user.cpp:49:60: warning: array subscript has type ‘char’ [-Wchar-subscripts] operands[++numberOfOperands] = characters[value]; ^ user.cpp:56:166: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (numberOfOperands != 0 && numberOfOperators != 0 && operators[numberOfOperators] != '(' && priority[operators[numberOfOperators]] >= priority[value]) { ^ user.cpp: In function ‘int main()’: user.cpp:71:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] characters[c] = !characters[c]; ^ user.cpp:71:38: warning: array subscript has type ‘char’ [-Wchar-subscripts] characters[c] = !characters[c]; ^ user.cpp: In function ‘void doSomeBoringStuff()’: user.cpp:92:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int index = 0; index < buffer.size(); ++index) { ^