Compilare: user.cpp: In function ‘int main()’: user.cpp:53:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cmap.in","r",stdin); ^ user.cpp:54:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cmap.out","w",stdout); ^ user.cpp:55:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:58:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&v[i].first,&v[i].second); ^ user.cpp: In function ‘long long int DivImp(int, int)’: user.cpp:26:15: warning: ‘t’ may be used uninitialized in this function [-Wmaybe-uninitialized] int k,t,mid=(st+dr)>>1; ^ user.cpp:26:13: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] int k,t,mid=(st+dr)>>1; ^ user.cpp:26:15: warning: ‘t’ may be used uninitialized in this function [-Wmaybe-uninitialized] int k,t,mid=(st+dr)>>1; ^ user.cpp:26:13: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] int k,t,mid=(st+dr)>>1; ^ user.cpp:26:15: warning: ‘t’ may be used uninitialized in this function [-Wmaybe-uninitialized] int k,t,mid=(st+dr)>>1; ^ user.cpp:26:13: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] int k,t,mid=(st+dr)>>1; ^