Compilare: main.cpp: In function 'void solve(int, int)': main.cpp:21:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (cr == s.length()) { ~~~^~~~~~~~~~~~~ main.cpp:27:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[node].size(); ++i) { ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:59:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j <= s.size(); ++j) { ~~^~~~~~~~~~~