Compilare: user.cpp: In function ‘int main()’: user.cpp:120:56: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < init_graph[i].size() / 2; ++ j) { ^ In file included from /usr/include/c++/4.8/cassert:43:0, from user.cpp:5: user.cpp:146:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] assert(sol.size() == m); ^