Compilare: main.cpp: In function 'void readInput()': main.cpp:18:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 2; j < s2.size(); ++j) ~~^~~~~~~~~~~ main.cpp:20:27: warning: array subscript has type 'char' [-Wchar-subscripts] constval[s2[0]] = nr; ^ main.cpp:23:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < s2.size(); ++j) ~~^~~~~~~~~~~ main.cpp:25:34: warning: array subscript has type 'char' [-Wchar-subscripts] functie[s2[0]] = s2.substr(j + 1, s2.size() - j - 1); ^ main.cpp: In function 'int termen(std::__cxx11::string, int&, int*)': main.cpp:36:32: warning: array subscript has type 'char' [-Wchar-subscripts] return val[exp[pos - 1]]; ^ main.cpp: In function 'int eval(std::__cxx11::string, int*)': main.cpp:55:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < exp.size()) { ~~~~^~~~~~~~~~~~ main.cpp: In function 'int apel(std::__cxx11::string)': main.cpp:72:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < exp.size()) { ~~~~^~~~~~~~~~~~ main.cpp:73:16: warning: array subscript has type 'char' [-Wchar-subscripts] val[lit] = termenFn(exp, pos); ^ main.cpp:77:31: warning: array subscript has type 'char' [-Wchar-subscripts] return eval(functie[exp[0]], val); ^ main.cpp: In function 'int termenFn(std::__cxx11::string, int&)': main.cpp:84:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (exp[pos] == ')' && pos == exp.size() - 1) ~~~~^~~~~~~~~~~~~~~~~ main.cpp:94:31: warning: array subscript has type 'char' [-Wchar-subscripts] return constval[aux[0]]; ^