Compilare: user.cpp: In function ‘void insert(circle)’: user.cpp:28:6: warning: unused variable ‘i’ [-Wunused-variable] int i = 0; ^ user.cpp: In function ‘bool isthere(circle)’: user.cpp:46:6: warning: unused variable ‘i’ [-Wunused-variable] int i = 0; ^ user.cpp: In function ‘int main()’: user.cpp:91:8: warning: unused variable ‘a’ [-Wunused-variable] int t,a,b; ^ user.cpp:91:10: warning: unused variable ‘b’ [-Wunused-variable] int t,a,b; ^ user.cpp:93:9: warning: variable ‘r2’ set but not used [-Wunused-but-set-variable] double r2,d,d2,x3,y3; ^ user.cpp:93:12: warning: unused variable ‘d’ [-Wunused-variable] double r2,d,d2,x3,y3; ^ user.cpp:93:14: warning: unused variable ‘d2’ [-Wunused-variable] double r2,d,d2,x3,y3; ^ user.cpp:93:17: warning: unused variable ‘x3’ [-Wunused-variable] double r2,d,d2,x3,y3; ^ user.cpp:93:20: warning: unused variable ‘y3’ [-Wunused-variable] double r2,d,d2,x3,y3; ^ user.cpp:94:9: warning: unused variable ‘x1’ [-Wunused-variable] double x1,y1,x2,y2; ^ user.cpp:94:12: warning: unused variable ‘y1’ [-Wunused-variable] double x1,y1,x2,y2; ^ user.cpp:94:15: warning: unused variable ‘x2’ [-Wunused-variable] double x1,y1,x2,y2; ^ user.cpp:94:18: warning: unused variable ‘y2’ [-Wunused-variable] double x1,y1,x2,y2; ^ user.cpp:95:9: warning: variable ‘c0’ set but not used [-Wunused-but-set-variable] circle c0 ; ^ user.cpp: In function ‘bool isthere(circle)’: user.cpp:60:1: warning: control reaches end of non-void function [-Wreturn-type] } ^