Compilare: user.cpp: In function ‘void Read()’: user.cpp:11:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("custi.in", "r", stdin); ^ user.cpp:12:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:15:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &mat[i][j]); ^ user.cpp: In function ‘void Write()’: user.cpp:21:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("custi.out", "w", stdout); ^