Compilare: user.cpp: In function ‘int main()’: user.cpp:48:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<answer.size(); ++i) ^ user.cpp:18:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j, byte, single = 0; ^ user.cpp:15:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dubi.in", "r", stdin); ^ user.cpp:16:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dubi.out", "w", stdout); ^ user.cpp:20:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^