Compilare: main.cpp: In function 'void ins(trie*, int, int)': main.cpp:25:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (index == x.size()){ ~~~~~~^~~~~~~~~~~ main.cpp: In function 'void del(trie*, int)': main.cpp:36:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (index == x.size()){ ~~~~~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:61:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < x.size(); ++j){ ~~^~~~~~~~~~ main.cpp:68:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < x.size(); ++j){ ~~^~~~~~~~~~