Compilare: main.cpp: In function 'void evaluate(int, int, int)': main.cpp:20:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ind<s.size()){ ~~~^~~~~~~~~ main.cpp: In function 'int get(int&, std::__cxx11::string&)': main.cpp:30:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ind<s.size()&&'0'<=s[ind]&&s[ind]<='9'){ ~~~^~~~~~~~~ main.cpp:37:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ind<s.size()&&'0'<=s[ind]&&s[ind]<='9'){ ~~~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:55:8: warning: unused variable 'ind' [-Wunused-variable] int ind=0; ^~~