Compilare: user.cpp: In function ‘void read()’: user.cpp:30:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "insule.in", "r", stdin ); ^ user.cpp:32:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d%c", &n, &m, &c ); ^ user.cpp:35:69: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%c", &c ), v[i][j] = c - '0', r[i][j] = v[i][j]; ^ user.cpp: In function ‘void write()’: user.cpp:71:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "insule.out", "w", stdout ); ^