Compilare: user.cpp: In function ‘void bellman_ford()’: user.cpp:41:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[start].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:111:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[i].size();j++) ^ user.cpp:138:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(idx=0;idx<l[start].size();idx++) ^