[蓝桥] 基础练习 十六进制转八进制(java)

 1 import java.util.Scanner;
 2 
 3 public class Main {
 4     public static void main(String[] args) {
 5         Scanner scanner = new Scanner(System.in);
 6         int n = scanner.nextInt();
 7         String[] str = new String[n];
 8         for(int i = 0;i < n;i++) {
 9             str[i] = scanner.next();
10         }
11         scanner.close();
12         for(int i = 0;i < n;i++) {
13             String strBinary = toBinary(str[i]);
14             int len_strBinary = strBinary.length();
15             if(len_strBinary % 3 == 1)
16                 strBinary = "00" + strBinary;
17             if(len_strBinary % 3 == 2)
18                 strBinary = "0" + strBinary;
19             String strOctal = toOctal(strBinary);
20             System.out.println(strOctal);
21         }
22     }
23     private static String toOctal(String strBinary) {
24         int len = strBinary.length();
25         int k;
26         StringBuffer stb = new StringBuffer();
27         if(strBinary.substring(0,3).equals("000"))
28             k = 3;
29         else
30             k = 0;
31         for(int i = k;i < len-2;i += 3) {
32             switch(strBinary.substring(i,i+3)) {
33                 case "000":stb.append("0");break;
34                 case "001":stb.append("1");break;
35                 case "010":stb.append("2");break;
36                 case "011":stb.append("3");break;
37                 case "100":stb.append("4");break;
38                 case "101":stb.append("5");break;
39                 case "110":stb.append("6");break;
40                 case "111":stb.append("7");break;
41                 default:break;
42             }
43         }
44         return stb.toString();
45     }
46     private static String toBinary(String strHex) {
47         int len = strHex.length();
48         StringBuffer stb = new StringBuffer();
49         for(int i = 0;i < len;i++) {
50             switch(strHex.charAt(i)) {
51                 case ‘0‘:stb.append("0000");break;
52                 case ‘1‘:stb.append("0001");break;
53                 case ‘2‘:stb.append("0010");break;
54                 case ‘3‘:stb.append("0011");break;
55                 case ‘4‘:stb.append("0100");break;
56                 case ‘5‘:stb.append("0101");break;
57                 case ‘6‘:stb.append("0110");break;
58                 case ‘7‘:stb.append("0111");break;
59                 case ‘8‘:stb.append("1000");break;
60                 case ‘9‘:stb.append("1001");break;
61                 case ‘A‘:stb.append("1010");break;
62                 case ‘B‘:stb.append("1011");break;
63                 case ‘C‘:stb.append("1100");break;
64                 case ‘D‘:stb.append("1101");break;
65                 case ‘E‘:stb.append("1110");break;
66                 case ‘F‘:stb.append("1111");break;
67                 default:break;
68             }
69         }
70         return stb.toString();
71     }
72 }