Compilare: user.cpp: In function ‘int main()’: user.cpp:39:12: warning: unused variable ‘a’ [-Wunused-variable] double a,b,c,s1,s2; ^ user.cpp:39:14: warning: unused variable ‘b’ [-Wunused-variable] double a,b,c,s1,s2; ^ user.cpp:39:16: warning: unused variable ‘c’ [-Wunused-variable] double a,b,c,s1,s2; ^ user.cpp:35:33: 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:36:35: 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:40:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&q); ^ user.cpp:44:82: 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",&p1.x,&p1.y,&p2.x,&p2.y,&p3.x,&p3.y,&p4.x,&p4.y); ^