Compilare: user.cpp: In function ‘void read()’: user.cpp:14:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hallway.in", "r", stdin); ^ user.cpp:15:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &m, &n, &k); ^ user.cpp:19:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &v[i + 2].x, &v[i + 2].y); ^ user.cpp: In function ‘void write()’: user.cpp:70:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hallway.out", "w", stdout); ^