Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:29: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void solve(int)’: user.cpp:87: warning: unused variable ‘i’ user.cpp:87: warning: unused variable ‘j’ user.cpp: In function ‘int main()’: user.cpp:142: warning: comparison between signed and unsigned integer expressions user.cpp:144: warning: comparison between signed and unsigned integer expressions