Compilare: user.cpp: In function ‘int main()’: user.cpp:68:6: warning: unused variable ‘i’ [-Wunused-variable] int i, k, sum = 0, nz = 0; ^ user.cpp:68:9: warning: unused variable ‘k’ [-Wunused-variable] int i, k, sum = 0, nz = 0; ^ user.cpp:68:12: warning: unused variable ‘sum’ [-Wunused-variable] int i, k, sum = 0, nz = 0; ^ user.cpp:68:21: warning: unused variable ‘nz’ [-Wunused-variable] int i, k, sum = 0, nz = 0; ^