Compilare: user.cpp: In function ‘int main()’: user.cpp:214:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("next.in","r",stdin); ^ user.cpp:215:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("next.out","w",stdout); ^ user.cpp:219:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(tmp); ^ user.cpp:223:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&d); ^ /tmp/ccUZpqrG.o: In function `main': user.cpp:(.text.startup+0x6b): warning: the `gets' function is dangerous and should not be used.