Compilare: user.cpp: In function ‘TRIE* add(TRIE*, char*, int)’: user.cpp:39:19: warning: NULL used in arithmetic [-Wpointer-arith] if(word[0] == NULL) ^ user.cpp: In function ‘int main()’: user.cpp:96:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < srt.size(); i++) ^ user.cpp:106:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 1; (1<<j) <= tata.size(); j++) ^ /tmp/ccTHP1or.o: In function `main': user.cpp:(.text.startup+0x164): warning: the `gets' function is dangerous and should not be used.