Compilare: user.cpp: In function ‘int main()’: user.cpp:15:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("stalpi3.in","r",stdin); ^ user.cpp:16:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("stalpi3.out","w",stdout); ^ user.cpp:19:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&D); ^ user.cpp:25:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&pos,&color); ^ user.cpp:33:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&pos,&color); ^ user.cpp:21:16: warning: ‘last_B’ may be used uninitialized in this function [-Wmaybe-uninitialized] int last_A,last_B; ^ user.cpp:21:9: warning: ‘last_A’ may be used uninitialized in this function [-Wmaybe-uninitialized] int last_A,last_B; ^