第3章 结构之法——电话号码对应英语单词

 1 package chapter3jiegouzhifa.TelephoneMapWords;
 2 /**
 3  * 电话号码对应英语单词
 4  * @author DELL
 5  *
 6  */
 7 public class TelephoneMapWords1 {
 8     private int telLength;  //电话号码的位数
 9     private char c[][]={  //各个数字所能代表的字符
10             "".toCharArray(),  //0
11             "".toCharArray(),    //1
12             "ABC".toCharArray(),    //2
13             "DEF".toCharArray(),    //3
14             "GHI".toCharArray(),    //4
15             "JKL".toCharArray(),    //5
16             "MNO".toCharArray(),    //6
17             "PQRS".toCharArray(),    //7
18             "TUV".toCharArray(),    //8
19             "WXYZ".toCharArray(),    //9            
20     };
21     private int total[]={0,0,3,3,3,3,3,4,3,4};  //每个数字所能代表的字符数
22     private int number[]; //电话号码
23     private int answer[];  //数字目前所代表的字符在其所能代表的字符集中的位置
24     //构造函数
25     public TelephoneMapWords1(int number[]){
26         this.number = number;
27         this.telLength = number.length;
28         answer = new int[telLength];
29     }
30     //输出电话号码对应英语单词
31     public void output(){
32         while(true){
33             for(int i=0;i<telLength;i++)
34                 System.out.print(c[number[i]][answer[i]]);
35             System.out.println();
36             int k = telLength - 1;
37             while(k>=0){
38                 if(answer[k]<total[number[k]]-1){
39                     answer[k]++;
40                     break;
41                 }else{
42                     answer[k]=0;
43                     k--;
44                 }
45             }
46             if(k<0)
47                 break;
48         }
49     }
50     public static void main(String[] args) {
51         int number[]={2,6,6,7,8,8,3,7};
52         TelephoneMapWords1 tmw = new TelephoneMapWords1(number);
53         tmw.output();
54 
55     }
56 
57 }

 1 package chapter3jiegouzhifa.TelephoneMapWords;
 2 /**
 3  * 电话号码对应英语单词
 4  * 【解法二】递归方法
 5  * @author DELL
 6  *
 7  */
 8 public class TelephoneMapWords2 {
 9     private int telLength;  //电话号码的位数
10     private char c[][]={  //各个数字所能代表的字符
11             "".toCharArray(),  //0
12             "".toCharArray(),    //1
13             "ABC".toCharArray(),    //2
14             "DEF".toCharArray(),    //3
15             "GHI".toCharArray(),    //4
16             "JKL".toCharArray(),    //5
17             "MNO".toCharArray(),    //6
18             "PQRS".toCharArray(),    //7
19             "TUV".toCharArray(),    //8
20             "WXYZ".toCharArray(),    //9            
21     };
22     private int total[]={0,0,3,3,3,3,3,4,3,4};  //每个数字所能代表的字符数
23     private int number[]; //电话号码
24     private int answer[];  //数字目前所代表的字符在其所能代表的字符集中的位置
25     //构造函数
26     public TelephoneMapWords2(int number[]){
27         this.number = number;
28         this.telLength = number.length;
29         answer = new int[telLength];
30     }
31     //输出电话号码对应英语单词
32     public void output(int index){
33         if(index==telLength){
34             for(int i=0;i<telLength;i++)
35                 System.out.print(c[number[i]][answer[i]]);
36             System.out.println();
37             return;
38         }
39         for(answer[index]=0;answer[index]<total[number[index]];answer[index]++){
40             output(index+1);
41         }
42     }
43     public static void main(String[] args) {
44         int number[]={2,6,6,7,8,8,3,7};
45         TelephoneMapWords2 tmw = new TelephoneMapWords2(number);
46         tmw.output(0);
47 
48     }
49 
50 }