Compilare: user.cpp: In function ‘int main()’: user.cpp:18:5: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(s); ^~~~ In file included from /usr/include/c++/6/cstdio:42:0, from user.cpp:1: /usr/include/stdio.h:638:14: note: declared here extern char *gets (char *__s) __wur __attribute_deprecated__; ^~~~ user.cpp:18:11: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(s); ^ In file included from /usr/include/c++/6/cstdio:42:0, from user.cpp:1: /usr/include/stdio.h:638:14: note: declared here extern char *gets (char *__s) __wur __attribute_deprecated__; ^~~~ user.cpp:28:20: warning: variable ‘dr’ set but not used [-Wunused-but-set-variable] int st,dr; ^~ user.cpp:16:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pali.in","r",stdin); ^ user.cpp:17:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pali.out","w",stdout); ^ user.cpp:18:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/ccbmyMzD.o: In function `main': user.cpp:(.text.startup+0x4e): warning: the `gets' function is dangerous and should not be used.