Compilare: user.cpp: In function ‘int main()’: user.cpp:40:34: 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:41:36: 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:42:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:47:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i][j]); ^ user.cpp:10:13: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] return i*nmax+j; ^ user.cpp:43:13: note: ‘x’ was declared here int i,j,x,y,max=0; ^ user.cpp:10:19: warning: ‘y’ may be used uninitialized in this function [-Wmaybe-uninitialized] return i*nmax+j; ^ user.cpp:43:15: note: ‘y’ was declared here int i,j,x,y,max=0; ^