Compilare: user.cpp: In constructor ‘TrieNode::TrieNode()’: user.cpp:23:61: warning: passing NULL to non-pointer argument 2 of ‘void* memset(void*, int, size_t)’ [-Wconversion-null] memset(children, NULL, sizeof(TrieNode*) * ALPHA_LEN); ^ user.cpp: In function ‘int main()’: user.cpp:99:43: 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); ^ user.cpp:100:45: 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); ^ user.cpp:104:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%s", text); ^ user.cpp:105:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &N); ^ user.cpp:110:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%s", words[i]); ^