Compilare: user.cpp:2:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main(){int a,b;freopen("adunare.in","r",stdin);freopen("adunare.out","w",stdout);scanf("%d%d",&a,&b);printf("%d",a+b);} ^ user.cpp: In function ‘int main()’: user.cpp:2:47: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] main(){int a,b;freopen("adunare.in","r",stdin);freopen("adunare.out","w",stdout);scanf("%d%d",&a,&b);printf("%d",a+b);} ^ user.cpp:2:81: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] main(){int a,b;freopen("adunare.in","r",stdin);freopen("adunare.out","w",stdout);scanf("%d%d",&a,&b);printf("%d",a+b);} ^ user.cpp:2:101: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] main(){int a,b;freopen("adunare.in","r",stdin);freopen("adunare.out","w",stdout);scanf("%d%d",&a,&b);printf("%d",a+b);} ^