Compilare: user.cpp: In function ‘int main()’: user.cpp:52:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < edges[x].size() ; i ++ ) ^ user.cpp:74:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = x ; i < nodes.size() ; i ++ ) ^ user.cpp:78:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( j = 0 ; j < edges[nodes[i].first].size() ; j ++ ) ^