Compilare: user.cpp: In function ‘int main()’: user.cpp:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘int prefix(trie*, char*, int)’: user.cpp:91: warning: control reaches end of non-void function user.cpp: In function ‘int aparitie(trie*, char*)’: user.cpp:84: warning: control reaches end of non-void function