Compilare: main.cpp: In function 'void add(Trie*, int)': main.cpp:28:6: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==S.length()) {nod->end++; return;} ~^~~~~~~~~~~~ main.cpp: In function 'int del(Trie*, int)': main.cpp:41:6: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==S.length()) nod->end--; ~^~~~~~~~~~~~ main.cpp: In function 'int query(Trie*, int)': main.cpp:58:6: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==S.length()) return nod->end; ~^~~~~~~~~~~~ main.cpp: In function 'int prefix(Trie*, int, int)': main.cpp:66:6: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==S.length() || nod->F[Q]==0) return k; ~^~~~~~~~~~~~