Compilare: user.cpp: In function ‘int main()’: user.cpp:68:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lant.in","r",stdin); ^ user.cpp:69:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lant.out","w",stdout); ^ user.cpp:71:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&K); ^ user.cpp:72:8: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(S); ^ user.cpp:84:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(S); ^ /tmp/cc8l9rud.o: In function `main': user.cpp:(.text.startup+0x68): warning: the `gets' function is dangerous and should not be used.