Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:19:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i < v[x].size();i++) { ^ user.cpp: In function ‘int main()’: user.cpp:33:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi, "%d%d", &N, &M); ^ user.cpp:36:37: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi, "%d", &v1[j]); ^