Compilare: user.cpp: In function ‘int main()’: user.cpp:28:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < q.size(); i++) ^ user.cpp:31:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < a[i].size(); j++) ^ user.cpp:58:56: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = x % s; i < a[x / s] .size(); i++) w += a[x / s][i]; ^