Compilare: main.cpp: In function 'int main()': main.cpp:52:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < s.size()) { ~~^~~~~~~~~~ main.cpp:87:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < s.size() && isdigit(s[i])) { ~~^~~~~~~~~~ main.cpp: In function 'int getresult(int, int, char)': main.cpp:29:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ main.cpp: In function 'int priority(char)': main.cpp:42:1: warning: control reaches end of non-void function [-Wreturn-type] } ^