n >= 6 的时候减3, 最后分类讨论, 上个Java
1 import java.math.BigInteger;
2 import java.util.*;
3
4
5 public class Main {
6 public static void main(String[] args) {
7 Scanner in = new Scanner(System.in);
8 int n = in.nextInt();
9 BigInteger ans = BigInteger.valueOf(1);
10 while(n >= 6) {
11 ans = ans.multiply(BigInteger.valueOf(3));
12 n -= 3;
13 }
14
15 if(n == 5) {
16 ans = ans.multiply(BigInteger.valueOf(6));
17 } else if(n == 4) {
18 ans = ans.multiply(BigInteger.valueOf(4));
19 } else if(n == 3) {
20 ans = ans.multiply(BigInteger.valueOf(3));
21 } else if(n == 2) {
22 ans = ans.multiply(BigInteger.valueOf(2));
23 }
24
25 String s = ans.toString();
26 System.out.println(s.length());
27 for(int i = 0; i < s.length() && i < 100; i++) {
28 System.out.print(s.charAt(i));
29 }
30 }
31 }