Compilare: user.cpp: In function ‘int main()’: user.cpp:41: warning: comparison between signed and unsigned integer expressions user.cpp:47: warning: unused variable ‘j’ user.cpp: In function ‘void calculate()’: user.cpp:67: warning: unused variable ‘k’ user.cpp: In function ‘void select(int)’: user.cpp:100: warning: comparison between signed and unsigned integer expressions user.cpp:88: warning: unused variable ‘nr’