Compilare: user.cpp: In function ‘void fix_failure()’: user.cpp:54:61: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < (now ->failure ->index).size(); i ++){ ^ user.cpp: In function ‘void search()’: user.cpp:87:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < (now ->index).size(); i ++){ ^ user.cpp:88:40: warning: array subscript has type ‘char’ [-Wchar-subscripts] ++ ord[(now ->index)[i]]; ^