Compilare: main.cpp: In function 'void Insert(Trie*, char*)': main.cpp:22:15: warning: NULL used in arithmetic [-Wpointer-arith] if(*word==NULL) ^~~~ main.cpp: In function 'void Erase(Trie*, char*)': main.cpp:34:15: warning: NULL used in arithmetic [-Wpointer-arith] if(*word==NULL) ^~~~ main.cpp: In function 'short int CountApparition(Trie*, char*)': main.cpp:43:15: warning: NULL used in arithmetic [-Wpointer-arith] if(*word==NULL) ^~~~ main.cpp: In function 'short int Prefix(Trie*, char*, short int)': main.cpp:51:15: warning: NULL used in arithmetic [-Wpointer-arith] if(*word==NULL||node->son[*word-'a']==NULL||node->son[*word-'a']->wordcount==0) ^~~~ main.cpp: In function 'int main()': main.cpp:59:36: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'short int*' [-Wformat=] while(scanf("%d%s", &type, word) == 2) ^