Compilare: user.cpp: In function ‘int main()’: user.cpp:13:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "plaja.in", "r", stdin ); ^ user.cpp:14:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( "plaja.out", "w", stdout ); ^ user.cpp:15:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d%d", &a, &b, &u ); ^ user.cpp:17:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d", &x[i], &y[i] ); ^ user.cpp:18:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d", &n ); ^ user.cpp:21:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d%d%d", &x1, &y1, &x2, &y2 ); ^ user.cpp:43:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for ( scanf ( "%d", &m ); m--; ) ^ user.cpp:45:52: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d %d %d %d", &x1, &y1, &x2, &y2 ); ^