Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:45:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i < v[nod].size();i++) { ^ user.cpp: In function ‘char next()’: user.cpp:17:41: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, BUF, fin), pos = 0; ^