Compilare: main.cpp: In function 'void add(std::__cxx11::string, int)': main.cpp:20:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp:26:23: warning: array subscript has type 'char' [-Wchar-subscripts] if(tree[poz].next[ch]!=0) ^ main.cpp:28:25: warning: array subscript has type 'char' [-Wchar-subscripts] poz=tree[poz].next[ch]; ^ main.cpp:37:21: warning: array subscript has type 'char' [-Wchar-subscripts] tree[poz].next[ch]=n; ^ main.cpp:41:49: warning: array subscript has type 'char' [-Wchar-subscripts] if(s[i-tree[f].len-1]==ch && tree[f].next[ch]!=0) ^ main.cpp:43:23: warning: array subscript has type 'char' [-Wchar-subscripts] f=tree[f].next[ch]; ^