Compilare: user.cpp: In function ‘void dfs2(int, int)’: user.cpp:106:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 1; i < lst1.size(); i ++ ) ^ user.cpp:109:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 1; i < arr.size(); i ++ ) { ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:14:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, fin); ^