SPBINARY - Xâu Nhị Phân
Tác giả: khuc_tuan
Ngôn ngữ: Java
import java.math.BigInteger;
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int k = sc.nextInt();
BigInteger[][] F = new BigInteger[n + 1][k + 1];
for (BigInteger[] aa : F)
Arrays.fill(aa, BigInteger.ZERO);
F[1][1] = BigInteger.valueOf(2);
for (int i = 1; i < n; ++i)
for (int j = 1; j <= k; ++j) {
F[i + 1][1] = F[i + 1][1].add(F[i][j]);
if (j < k)
F[i + 1][j + 1] = F[i + 1][j + 1].add(F[i][j]);
}
BigInteger total = BigInteger.ZERO;
for (int i = 1; i <= k; ++i)
total = total.add(F[n][i]);
System.out.println(total);
}
}