Compilare: user.cpp: In function ‘int main()’: user.cpp:25:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1; i<=M; i++) ^ user.cpp:31:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1; i<=N; i++) /// We are testing if we have an Euler cycle. ^ user.cpp: In function ‘void DFS(int)’: user.cpp:45:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos[node] < G[node].size()) /// While node has neighbors... ^