Compilare: user.cpp: In function ‘void Print()’: user.cpp:67:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<answer.size (); i++, printf ("\n")) ^ user.cpp: In function ‘int main()’: user.cpp:74:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("biconex.in", "r", stdin); ^ user.cpp:75:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("biconex.out", "w", stdout); ^ user.cpp:77:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &N, &M); ^ user.cpp:82:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &x, &y); ^