Compilare: 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; ^ user.cpp: In function ‘int main()’: user.cpp:60:13: warning: ‘rad’ may be used uninitialized in this function [-Wmaybe-uninitialized] dfs(rad); ^