Compilare: user.cpp: In function ‘int main()’: user.cpp:21:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("laser.in", "r", stdin); ^ user.cpp:22:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("laser.out", "w", stdout); ^ user.cpp:24:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &n); ^ user.cpp:28:58: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d %d", &a1[i], &b1[i], &a2[i], &b2[i]); ^ user.cpp:44:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &tip[i]); ^