Compilare: user.cpp: In function ‘int main()’: user.cpp:15:12: warning: unused variable ‘x1’ [-Wunused-variable] int i, x1, y1, x2, y2, j, ans; ^ user.cpp:15:16: warning: unused variable ‘y1’ [-Wunused-variable] int i, x1, y1, x2, y2, j, ans; ^ user.cpp:15:20: warning: unused variable ‘x2’ [-Wunused-variable] int i, x1, y1, x2, y2, j, ans; ^ user.cpp:15:24: warning: unused variable ‘y2’ [-Wunused-variable] int i, x1, y1, x2, y2, j, ans; ^ user.cpp:17:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("camion.in", "r", stdin); ^ user.cpp:18:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("camion.out", "w", stdout); ^ user.cpp:20:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d%d", &n, &m, &k, &c); ^ user.cpp:22:71: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d%d", &D [i].x1, &D [i].y1, &D [i].x2, &D [i].y2); ^