Compilare: user.cpp: In function ‘void Back1(int, int)’: user.cpp:73:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘void Back2(int, int)’: user.cpp:121:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘int main()’: user.cpp:136:8: warning: unused variable ‘i’ [-Wunused-variable] int i,j; ^ user.cpp:136:10: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^