Compilare: user.cpp: In function ‘int main()’: user.cpp:48:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < v.size (); ++i) ^ user.cpp:20:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("poligon6.in", "r", stdin); ^ user.cpp:21:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("poligon6.out", "w", stdout); ^ user.cpp:24:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &n); ^ user.cpp:29:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &a); ^