Compilare: user.cpp: In function ‘int main()’: user.cpp:82:13: warning: unused variable ‘x1’ [-Wunused-variable] int x1,x2,y1,y2; ^ user.cpp:82:16: warning: unused variable ‘x2’ [-Wunused-variable] int x1,x2,y1,y2; ^ user.cpp:82:19: warning: unused variable ‘y1’ [-Wunused-variable] int x1,x2,y1,y2; ^ user.cpp:82:22: warning: unused variable ‘y2’ [-Wunused-variable] int x1,x2,y1,y2; ^