Compilare: user.cpp: In function 'long long int solve(int, std::string)': user.cpp:24: warning: comparison between signed and unsigned integer expressions user.cpp:24: warning: comparison between signed and unsigned integer expressions user.cpp:26: warning: comparison between signed and unsigned integer expressions user.cpp:26: warning: comparison between signed and unsigned integer expressions user.cpp:28: warning: comparison between signed and unsigned integer expressions user.cpp:29: warning: comparison between signed and unsigned integer expressions user.cpp:29: warning: comparison between signed and unsigned integer expressions user.cpp:31: warning: comparison between signed and unsigned integer expressions