Compilare: user.cpp: In function ‘int main()’: user.cpp:43:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < sizeof(a[0]); i++) ^ user.cpp:34:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, k; ^ user.cpp:34:15: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k; ^ user.cpp:35:9: warning: unused variable ‘element’ [-Wunused-variable] int element; ^