Compilare: main.cpp: In function 'trie* Insert(trie*, char*)': main.cpp:35:12: warning: NULL used in arithmetic [-Wpointer-arith] if(*s==NULL) ^~~~ main.cpp: In function 'int main()': main.cpp:62:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ahocorasick.in","r",stdin); ^ main.cpp:63:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ahocorasick.out","w",stdout); ^ main.cpp:65:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s",str); ^ main.cpp:69:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:73:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s",s); ^