Compilare: user.cpp: In function ‘void bfs1(int, bool*)’: user.cpp:28:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<l[x].size();++i) ^ user.cpp: In function ‘int bfs()’: user.cpp:48:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<l[x].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:108:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<sol.size();++i) ^