Compilare: user.cpp: In function ‘void solve(int)’: user.cpp:38:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[crt].size(); ++i) ^ user.cpp:42:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < v[frd].size(); ++j) ^ user.cpp:65:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < answer.size(); ++i) ^