Compilare: user.cpp: In function ‘int main()’: user.cpp:80:9: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(sir+1); ^~~~ 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:80:19: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(sir+1); ^ 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:73:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cli.in","r",stdin); ^ user.cpp:74:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cli.out","w",stdout); ^ user.cpp:76:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n",&n,&k); ^ user.cpp:80:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sir+1); ^ /tmp/ccP0cR6K.o: In function `main': user.cpp:(.text.startup+0xdc): warning: the `gets' function is dangerous and should not be used.