fj,k=∑i=1V(i−1)j−1×(V−i)n−j−k+1×if_{j,k}=\sum_{i=1}^V (i-1)^{j-1} \times (V-i)^{n-j-k+1} \times ifj,k=∑i=1V(i−1)j−1×(V−i)n−j−k+1×i
有没有低于O(n2V)O(n^2V)O(n2V)的方法求出所有fj,kf_{j,k}fj,k
