Compilare: user.cpp: In constructor ‘trie_tree::trie::trie()’: user.cpp:20:23: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null] cnt_words = NULL; ^ user.cpp:21:26: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null] cnt_children = NULL; ^ user.cpp: In function ‘int main()’: user.cpp:107:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "trie.in" ,"r", stdin ); ^ user.cpp:108:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "trie.out","w", stdout ); ^ user.cpp:111:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%s", String ); ^