Compilare: user.cpp: In function ‘int main()’: user.cpp:28: warning: comparison between signed and unsigned integer expressions user.cpp:29: warning: comparison between signed and unsigned integer expressions user.cpp:30: warning: comparison between signed and unsigned integer expressions user.cpp:40: warning: comparison between signed and unsigned integer expressions user.cpp:41: warning: comparison between signed and unsigned integer expressions user.cpp:42: warning: comparison between signed and unsigned integer expressions user.cpp:60: warning: comparison between signed and unsigned integer expressions user.cpp:61: warning: comparison between signed and unsigned integer expressions user.cpp:62: warning: comparison between signed and unsigned integer expressions user.cpp:16: warning: ‘mid’ may be used uninitialized in this function