Compilare: user.cpp: In function ‘int main()’: user.cpp:63:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qtri.in", "r", stdin); ^ user.cpp:64:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qtri.out","w", stdout); ^ user.cpp:70:89: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d %d %d %d %d", &A.x, &A.y, &B.x, &B.y, &C.x, &C.y, &D.x, &D.y); ^