Compilare: user.cpp: In function ‘int main()’: user.cpp:16:9: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(a); ^ In file included from /usr/include/c++/5/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:16:9: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(a); ^ In file included from /usr/include/c++/5/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:16:15: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(a); ^ In file included from /usr/include/c++/5/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:10:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("delfin.in","r",stdin); ^ user.cpp:11:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("delfin.out","w",stdout); ^ user.cpp:12:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n",&n,&m); ^ user.cpp:16:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a); ^ /tmp/cc4nn7ck.o: In function `main': user.cpp:(.text.startup+0x99): warning: the `gets' function is dangerous and should not be used.