Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:16:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < graph[x].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:28:15: warning: unused variable ‘c’ [-Wunused-variable] int i, a, b, c, ok = 0; ^ user.cpp:28:18: warning: unused variable ‘ok’ [-Wunused-variable] int i, a, b, c, ok = 0; ^