Step by step learning Java array Learning (CH5) count 3 return 1 record the last position left in the queue

I spoke about the Java course just now, but I have already learned it in the video. Let's review it. The students all said that the Java teacher did not speak well,

In my opinion, the teacher is a good person, but not a good teacher .. Maybe he was a programmer at that time .. Hopefully,

But now .. It's a bit lazy. It's not a good talk .. However, after reading the video of Shang xuexiang, I saw Chapter 2 _ arrays _ exercise 8. Remember the code by yourself.

I typed it again .. It will be used for future reference .. I am not a plagiarize .. Just record it and use 2011-11-1911: 12: 18

 1 public class Test{
 2     public static void main(String[] args){
 3         boolean[] a = new boolean[500];
 4         for(int i=0;i<a.length;i++){
 5             a[i] = true;
 6         }
 7         
 8         int leftcount = a.length;
 9         int count = 0;
10         int index = 0;
11         while(leftcount>1){
12             if(a[index]==true){
13                 count++;
14                 if(count == 3){
15                     leftcount--;
16                     a[index] = false;
17                     count=0;
18                 }
19             }
20             index++;
21             if(index == a.length){
22                 index = 0;
23             }
24         }
25         for(int i=0;i<a.length;i++){
26             if(a[i] == true){
27                 System.out.println(i);
28             }
29         }
30     }
31 }

This is achieved by using the loop linked list ..

 1 public class Count3Quit1{
 2     public static void main(String[] args){
 3         
 4         KidCircle kc = new KidCircle(500);
 5         Kid k = kc.first;
 6         int countNum = 0;
 7         while(kc.count>1){
 8             countNum ++;
 9             if(countNum==3){
10                 countNum = 0;
11                 kc.delete(k);
12                 
13             }
14             k = k.right;
15         }  
16         System.out.println(kc.first.id);
17     
18     }
19 }
20 
21 
22 class Kid{
23     int id;
24     Kid left;
25     Kid right;
26 }
27 
28 class KidCircle{
29     int count = 0;
30     Kid first,last;
31     
32     KidCircle(int n){
33         for(int i=0;i<n;i++){
34                 add();
35         }
36         
37     }
38     
39     void add(){
40         Kid k = new Kid();
41         k.id = count;
42         if(count<=0){
43             k.left = k;
44             k.right = k;
45             first = k;
46             last = k;
47         }else {
48             last.right = k;
49             k.left = last;
50             k.right = first;
51             first.left = k;
52             last = k;
53         }
54         count ++;
55     }
56     
57     void delete(Kid k){
58         if(count<=0){
59             return;
60         }else if(count==1){
61             first = last = null;
62         }else{
63             k.left.right = k.right; 
64             k.right.left = k.left;
65              
66             
67             
68             if(k == first){
69                 first = k.right;
70             }else if(k == last){
71                 last = k.left;
72             }
73         }
74         count --;
75     }
76     
77 }