Compilare: user.cpp: In function ‘void init()’: user.cpp:17: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void solve()’: user.cpp:29: warning: comparison between signed and unsigned integer expressions user.cpp:32: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:48: warning: comparison between signed and unsigned integer expressions