Compilare: user.cpp:3:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main(){int a,b;fscanf(x"in","r"),"%d%d",&a,&b);fprintf(x"out","w"),"%d",a+b);} ^ user.cpp: In function ‘int main()’: user.cpp:3:47: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] main(){int a,b;fscanf(x"in","r"),"%d%d",&a,&b);fprintf(x"out","w"),"%d",a+b);} ^