Compilare: user.cpp: In function ‘int main()’: user.cpp:25:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("string.in","r",stdin); ^ user.cpp:26:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("string.out","w",stdout); ^ user.cpp:29:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ user.cpp:58:21: warning: ‘lastsol’ may be used uninitialized in this function [-Wmaybe-uninitialized] if ((lastsol&(1<<i))!=0) ^