Compilare: user.cpp: In function ‘int main()’: user.cpp:55:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alpin.in","r",stdin); ^ user.cpp:56:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alpin.out","w",stdout); ^ user.cpp:60:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:67:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i][j]); ^ user.cpp:81:16: warning: ‘j0’ may be used uninitialized in this function [-Wmaybe-uninitialized] drum(i0,j0); ^ user.cpp:81:16: warning: ‘i0’ may be used uninitialized in this function [-Wmaybe-uninitialized]