Compilare: user.cpp: In function ‘void cit()’: user.cpp:18:17: warning: NULL used in arithmetic [-Wpointer-arith] while(s[i]!=NULL){ ^ user.cpp:17:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ user.cpp: In function ‘int main()’: user.cpp:36:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("secventa.in","r",stdin); ^ user.cpp:37:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("secventa.out","w",stdout); ^ user.cpp:40:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d\n",&n,&k); ^ /tmp/cccIQXZX.o: In function `cit()': user.cpp:(.text+0x16): warning: the `gets' function is dangerous and should not be used.