Compilare: user.cpp: In function ‘bool AddLetter(int, bool, int)’: user.cpp:41:31: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (tree[node].next[letter] != 0) { ^ user.cpp:42:40: warning: array subscript has type ‘char’ [-Wchar-subscripts] suffix = tree[node].next[letter]; ^ user.cpp:52:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] tree[node].next[letter] = nodes; ^ user.cpp:60:58: warning: array subscript has type ‘char’ [-Wchar-subscripts] tree[nodes].fail = tree[node].next[letter]; ^ user.cpp: In function ‘int main()’: user.cpp:70:14: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] cin >> s + 1; ^ user.cpp:72:18: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] cin >> s + n + 1; ^