计蒜客 挑战难题 整数转换成罗马数字

 1 import java.util.Scanner;
 2 public class Main
 3 { 
 4     public static void main(String[] args) 
 5     { 
 6         Scanner input = new Scanner(System.in);
 7         System.out.println(run(input.nextInt()));
 8     }
 9     public static String run(int n)
10     {
11         String a="",b="",c="",d="",e="";
12         /**
13          * 轉化千位數
14          */
15         if((n/1000)%10 > 0)
16         {
17             for(int i=0;i<(n/1000)%10;i++)
18             {
19                 d +="M";
20             }
21         }
22         /**
23          * 轉換百位數
24          */
25         if((n/100)%10 > 0)
26         {
27             switch((n/100)%10)
28             {
29                 case 1: c="C";break;
30                 case 2: c="CC";break;
31                 case 3: c="CCC";break;
32                 case 4: c="CD";break;
33                 case 5: c="D";break;
34                 case 6: c="DC";break;
35                 case 7: c="DCC";break;
36                 case 8: c="DCCC";break;
37                 case 9: c="CM";break;
38             }
39         }
40         /**
41          * 轉化十位數
42          */
43         if((n/10)%10 > 0)
44         {
45             switch((n/10)%10)
46             {
47                 case 1: b="X";break;
48                 case 2: b="XX";break;
49                 case 3: b="XXX";break;
50                 case 4: b="XL";break;
51                 case 5: b="L";break;
52                 case 6: b="LX";break;
53                 case 7: b="LXX";break;
54                 case 8: b="LXXX";break;
55                 case 9: b="XC";break;
56             }
57         }
58         /**
59          * 轉換個位數
60          */
61         if(n%10 > 0)
62         {
63             switch(n%10)
64             {
65                 case 1: a="I";break;
66                 case 2: a="II";break;
67                 case 3: a="III";break;
68                 case 4: a="IV";break;
69                 case 5: a="V";break;
70                 case 6: a="VI";break;
71                 case 7: a="VII";break;
72                 case 8: a="VIII";break;
73                 case 9: a="IX";break;
74             }
75         }
76         e =  d + c + b + a;
77         return e;
78     }
79 }