Compilare: user.cpp: In function ‘void DFS(int, int)’: user.cpp:65:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < M[x].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:25:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d%d%d", &n, &m, &p, &q);//fin >> n >> m >> p >> q; ^ user.cpp:28:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &x, &y);//fin >> x >> y; ^