Compilare: user.cpp: In function ‘void trie_insert(Node*, int, std::string&)’: user.cpp:37:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos >= word.size()) { ^ user.cpp: In function ‘int trie_delete(Node*, int, std::string&)’: user.cpp:49:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos >= word.size()) { ^ user.cpp: In function ‘int trie_frequence(Node*, int, std::string&)’: user.cpp:64:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos >= word.size()) { ^ user.cpp: In function ‘int trie_lcp(Node*, int, std::string&)’: user.cpp:72:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos >= word.size()) { ^