Compilare: user.cpp: In function ‘int main()’: user.cpp:50:41: 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:51:43: 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:52:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets( expr ); ^ /tmp/ccbT3e9v.o: In function `main': user.cpp:(.text.startup+0x53): warning: the `gets' function is dangerous and should not be used.