Compilare: main.cpp: In function 'void add_word(nod_trie*, char*)': main.cpp:24:14: warning: NULL used in arithmetic [-Wpointer-arith] if(*cuv==NULL) ^~~~ main.cpp: In function 'int search_word(nod_trie*, char*)': main.cpp:40:14: warning: NULL used in arithmetic [-Wpointer-arith] if(*cuv==NULL) ^~~~ main.cpp: In function 'int delete_word(nod_trie*, char*)': main.cpp:54:14: warning: NULL used in arithmetic [-Wpointer-arith] if(*cuv==NULL) ^~~~ main.cpp: In function 'int prefix_length(nod_trie*, char*)': main.cpp:81:14: warning: NULL used in arithmetic [-Wpointer-arith] if(*cuv==NULL || nod->fii[delta]==NULL) ^~~~ main.cpp: In function 'int search_word(nod_trie*, char*)': main.cpp:50:1: warning: control reaches end of non-void function [-Wreturn-type] } ^