bzoj 1263 [SCOI2006]整数划分

n >= 6 的时候减3, 最后分类讨论， 上个Java

import java.math.BigInteger;
import java.util.*;


public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        BigInteger ans = BigInteger.valueOf(1);
        while(n >= 6) {
            ans = ans.multiply(BigInteger.valueOf(3));
            n -= 3;
        }
        
        if(n == 5) {
            ans = ans.multiply(BigInteger.valueOf(6));
        } else if(n == 4) {
            ans = ans.multiply(BigInteger.valueOf(4));
        } else if(n == 3) {
            ans = ans.multiply(BigInteger.valueOf(3));
        } else if(n == 2) {
            ans = ans.multiply(BigInteger.valueOf(2));
        }
        
        String s = ans.toString();
        System.out.println(s.length());
        for(int i = 0; i < s.length() && i < 100; i++) {
            System.out.print(s.charAt(i));
        }
    }
}