Compilare: main.cpp: In function 'bool isInvalid()': main.cpp:25:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 25 | for (int i = 0; i < s.size(); i++) | ~~^~~~~~~~~~ main.cpp: In function 'int calcul(char, char)': main.cpp:53:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 53 | while (it < s.size() && s[it] != otherOp && s[it] != ')') | ~~~^~~~~~~~~~ main.cpp:65:52: warning: array subscript has type 'char' [-Wchar-subscripts] 65 | ways = calcul(nextOp[it], opp[nextOp[it]]); | ~~~~~~~~~^ main.cpp:50:10: warning: unused variable 'multiplying' [-Wunused-variable] 50 | bool multiplying = 0; | ^~~~~~~~~~~ main.cpp: In function 'void solve()': main.cpp:107:43: warning: array subscript has type 'char' [-Wchar-subscripts] 107 | int x = calcul(nextOp[0], opp[nextOp[0]]); | ~~~~~~~~^