Compilare: user.cpp: In function ‘int main()’: user.cpp:25:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("metrou4.in", "r", stdin); ^ user.cpp:26:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("metrou4.out", "w", stdout); ^ user.cpp: In function ‘void apm()’: user.cpp:81:52: warning: ‘vecin’ may be used uninitialized in this function [-Wmaybe-uninitialized] d = modul(P[i].x - P[j].x) + modul(P[i].y - P[j].y); ^ user.cpp:57:7: note: ‘vecin’ was declared here int vecin; ^