Compilare: user.cpp: In function ‘int main()’: user.cpp:92:8: warning: unused variable ‘a’ [-Wunused-variable] int t,a,b; ^ user.cpp:92:10: warning: unused variable ‘b’ [-Wunused-variable] int t,a,b; ^ user.cpp:95:9: warning: unused variable ‘x1’ [-Wunused-variable] double x1,y1,x2,y2; ^ user.cpp:95:12: warning: unused variable ‘y1’ [-Wunused-variable] double x1,y1,x2,y2; ^ user.cpp:95:15: warning: unused variable ‘x2’ [-Wunused-variable] double x1,y1,x2,y2; ^ user.cpp:95:18: warning: unused variable ‘y2’ [-Wunused-variable] double x1,y1,x2,y2; ^