Compilare: user.cpp: In function ‘int main()’: user.cpp:31:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("seti.in","r",stdin); ^ user.cpp:32:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("seti.out","w",stdout); ^ user.cpp:33:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:34:27: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(ss,1,n*64+n+1,stdin); s1=ss; ^ user.cpp:50:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&m); gets(ss); ^ user.cpp:50:25: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&m); gets(ss); ^ user.cpp:52:15: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(ss+1); curenthash=0; n=strlen(ss+1); ^ /tmp/cc4GWsIa.o: In function `main': user.cpp:(.text.startup+0x3bd): warning: the `gets' function is dangerous and should not be used.