Compilare: user.cpp: In function ‘int bfs(int)’: user.cpp:30:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<G[x].size(); ++i) ^ user.cpp: In function ‘void dfs(int, int)’: user.cpp:45:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<G[x].size(); ++i) ^ user.cpp: In function ‘void solve()’: user.cpp:59:9: warning: unused variable ‘l’ [-Wunused-variable] int l; ^