Compilare: user.cpp: In function ‘void read()’: user.cpp:86:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("evaluare.in", "r", stdin); ^ user.cpp:87:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("evaluare.out", "w", stdout); ^ user.cpp:88:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", expr); ^