Compilare: user.cpp: In function ‘int main()’: user.cpp:19:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen (FIN, "r", stdin); ^ user.cpp:20:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen (FOU, "w", stdout); ^ user.cpp:22:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &N); ^ user.cpp: In function ‘bool cit(int&)’: user.cpp:12:52: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if ( ch[0] == '\0' ) fread ( ch, 1, hg, stdin ); ^ user.cpp:13:10: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] else for ( ; (ch[poz] < '0' || ch[poz] > '9') && ch[poz] != '\n'; verf ) ; ^ user.cpp:14:5: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] for ( x = 0 ; ch[poz] >= '0' && ch[poz] <= '9' ; x = x * 10 + ch[poz] - '0', verf ) ; ^