Compilare: user.cpp: In function ‘trie* add(trie*, char*)’: user.cpp:42:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] nod->nxt[v[0]]=add(nod->nxt[v[0]],v+1); ^ user.cpp:42:34: warning: array subscript has type ‘char’ [-Wchar-subscripts] nod->nxt[v[0]]=add(nod->nxt[v[0]],v+1); ^ user.cpp: In function ‘int main()’: user.cpp:100:20: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d",&n); ^ user.cpp:101:28: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(input,6<<20,1,in); ^