Compilare: user.cpp: In function ‘int main()’: user.cpp:41:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("spion.in", "r", stdin); ^ user.cpp:42:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("spion.out", "w", stdout); ^ user.cpp:45:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &cer); ^ user.cpp:46:10: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/cchu4La0.o: In function `main': user.cpp:(.text.startup+0x68): warning: the `gets' function is dangerous and should not be used.