Compilare: main.cpp: In function 'void add(Trie*, int)': main.cpp:22:25: warning: array subscript has type 'char' [-Wchar-subscripts] if(nod -> son[ch] == NULL) { ^ main.cpp:23:26: warning: array subscript has type 'char' [-Wchar-subscripts] nod -> son[ch] = new Trie; ^ main.cpp:25:26: warning: array subscript has type 'char' [-Wchar-subscripts] add(nod -> son[ch], pos + 1); ^ main.cpp: In function 'int main()': main.cpp:80:31: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&n,&k); ^ main.cpp:82:29: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(str, MAXN, fi); ^