Compilare: user.cpp: In function ‘int main()’: user.cpp:40:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[a1][a2]=v[a2][a1]=0; ^ user.cpp:40:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[a1][a2]=v[a2][a1]=0; ^ user.cpp:40:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[a1][a2]=v[a2][a1]=0; ^ user.cpp:40:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[a1][a2]=v[a2][a1]=0; ^ user.cpp:28:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nrcuv.in","r",stdin); ^ user.cpp:29:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nrcuv.out","w",stdout); ^ user.cpp:30:25: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(f,1,MAX,stdin); ^