Compilare: user.cpp: In function ‘int main()’: user.cpp:49:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<sol.size();i++) printf("%c",sol[i]); ^ user.cpp:42:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biti.in","r",stdin); ^ user.cpp:43:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biti.out","w",stdout); ^ user.cpp:44:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^