Compilare: user.cpp: In function ‘void read()’: user.cpp:28:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:30:66: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &v1[i].x, &v1[i].y, &v2[i].x, &v2[i].y); ^ user.cpp: In function ‘int main()’: user.cpp:77:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("geometry.in", "r", stdin); ^ user.cpp:78:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("geometry.out", "w", stdout); ^