Compilare: user.cpp:3:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main(){freopen("stramosi.in","r",stdin);freopen("stramosi.out","w",stdout); ^ user.cpp: In function ‘int main()’: user.cpp:3:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] main(){freopen("stramosi.in","r",stdin);freopen("stramosi.out","w",stdout); ^ user.cpp:3:75: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] main(){freopen("stramosi.in","r",stdin);freopen("stramosi.out","w",stdout); ^ user.cpp:4:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:5:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=0;i++<n;)scanf("%d",a[0]+i); ^ user.cpp:7:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(;m--;){scanf("%d %d",&j,&i); ^