Compilare: user.c: In function ‘add’: user.c:20:5: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(p->next[*word]==NULL) ^ user.c:21:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] p->next[*word] = (node*) calloc(1, sizeof(node)); ^ user.c:22:5: warning: array subscript has type ‘char’ [-Wchar-subscripts] add(p->next[*word], word+1); ^ user.c: In function ‘rem’: user.c:30:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] rem(p->next[*word], word+1); ^ user.c:31:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(p->next[*word]->pref==0){ ^ user.c:32:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] free(p->next[*word]); ^ user.c:33:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] p->next[*word] = NULL; ^ user.c: In function ‘get_count’: user.c:42:5: warning: array subscript has type ‘char’ [-Wchar-subscripts] return get_count(p->next[*word], word+1); ^ user.c: In function ‘max_pref’: user.c:48:5: warning: array subscript has type ‘char’ [-Wchar-subscripts] return 1+max_pref(p->next[*word], word+1); ^ user.c: In function ‘main’: user.c:76:19: warning: ‘res’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%d\n", res); ^