Compilare: main.cpp: In function 'int main()': main.cpp:2:51: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] int main(){int a,b;freopen("adunare.in","r",stdin);scanf("%d%d",&a,&b);freopen("adunare.out","w",stdout);printf("%d",a+b);} ^ main.cpp:2:71: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] int main(){int a,b;freopen("adunare.in","r",stdin);scanf("%d%d",&a,&b);freopen("adunare.out","w",stdout);printf("%d",a+b);} ^ main.cpp:2:105: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] int main(){int a,b;freopen("adunare.in","r",stdin);scanf("%d%d",&a,&b);freopen("adunare.out","w",stdout);printf("%d",a+b);} ^