Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[nod].size();i++){ ^ user.cpp: In function ‘void dfs2(int)’: user.cpp:27:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[nod].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:44:28: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (s,1,4000000,fin); ^