Compilare: user.cpp: In function `void insert(int, int, int)': user.cpp:9: warning: comparison between signed and unsigned integer expressions user.cpp:9: warning: comparison between signed and unsigned integer expressions user.cpp:13: warning: comparison between signed and unsigned integer expressions user.cpp:18: warning: comparison between signed and unsigned integer expressions user.cpp: In function `void pay(int, int, int)': user.cpp:27: warning: comparison between signed and unsigned integer expressions user.cpp:27: warning: comparison between signed and unsigned integer expressions user.cpp:32: warning: comparison between signed and unsigned integer expressions user.cpp:37: warning: comparison between signed and unsigned integer expressions user.cpp: In function `long long unsigned int quest(int, int, int)': user.cpp:46: warning: comparison between signed and unsigned integer expressions user.cpp:46: warning: comparison between signed and unsigned integer expressions user.cpp:51: warning: comparison between signed and unsigned integer expressions user.cpp:52: warning: comparison between signed and unsigned integer expressions