poj 2094 多项式求和。

 /**
 给出多项式 p(x) = an*x^n + an-1*x^(n-1)..... + a1*x + a0;
 给定n，l，k，m 计算 x 从 l到 l+k-1 的p（x）的后m 位的平方的和

 用差分序列 ，先计算出前 n项 构造出差分表。。后边的k-n个  用递推可得，从下往上递推。
 **/

 import java.math.BigInteger;
 import java.util.Scanner;

 public class Main {

         public static int cal(String str, int m) {
                // System.out.println(str+"------->");
                int len = Math.min(str.length(), m);
                int ans = , tmp;
                for (int i = ; i < len; i++) {
                      tmp = str.charAt(i) - '';
                      ans += tmp * tmp;
               }
                return ans;
        }

         public static void main(String[] args) {
               Scanner cin = new Scanner(System. in);
                int n = cin.nextInt();
               BigInteger l = cin.nextBigInteger();
                int k = cin.nextInt();
                int m = cin.nextInt();
               BigInteger mod = BigInteger. TEN.pow(m);
               BigInteger[] a = new BigInteger[];
                for (int i = ; i <= n; i++)
                      a[i] = cin.nextBigInteger();
               BigInteger h[][] = new BigInteger[][];
                for (int i = ; i < Math.min (n + , k); i++) {
                      BigInteger res = a[];
                       for (int j = ; j <= n; j++) {
                            res = res.multiply(l);
                            res = res.add(a[j]);
                      }
                      res = res.mod(mod);
                      l = l.add(BigInteger. ONE);
                      h[][i] = res;
                      System. out.println(cal(res.toString(), m));
               }

                if (k > n + ) {
                       for (int i = ; i <= n; i++) {
                             for (int j = ; j <= n - i; j++)
                                   h[i][j] = h[i - ][j + ].subtract(h[i - ][j]);
                      }
               }

               BigInteger pre[] = new BigInteger[];
                for (int i = ; i <= n; i++) {
                      pre[i] = h[i][n - i];
               }
                for (int i = n + ; i < k; i++) {
                      BigInteger res = h[n][];
                       for (int j = n - ; j >= ; j--) {
                            res = pre[j].add(res);
                            res = res.mod(mod);
                            pre[j] = res;
                      }
                      System. out.println(cal(res.toString(), m));
               }
        }

 }