Compilare: user.cpp: In function ‘int main()’: user.cpp:226:6: warning: unused variable ‘len’ [-Wunused-variable] int len = strlen(s); ^ user.cpp: In function ‘int Priority(char)’: user.cpp:27:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int DoOperator(int, int, char)’: user.cpp:46:1: warning: control reaches end of non-void function [-Wreturn-type] } ^