Compilare: user.cpp: In function 'int main()': user.cpp:26: warning: right-hand operand of comma has no effect user.cpp:26: warning: right-hand operand of comma has no effect user.cpp:51: warning: comparison between signed and unsigned integer expressions user.cpp:68: warning: comparison between signed and unsigned integer expressions user.cpp:75: warning: comparison between signed and unsigned integer expressions user.cpp:22: warning: unused variable 'j'