小白笔记----JAVA小程序数三减一（来自马士兵视屏）

public class Count3Qiut2 {

public static void main(String[] args) {
KidCircle kc = new KidCircle(500);
int countNum = 0;
Kid k = kc.first ;
while(kc.count > 1){
countNum++;
if(countNum == 3){
countNum = 0;
kc.delete(k);
}
k = k.right;
}
System.out.println(kc.first.id);
}
}

class Kid{
int id;
Kid left;
Kid right;
}

class KidCircle{
int count = 0;
Kid first;
Kid last;
KidCircle(int n){
for(int i = 0;i < n;i++){
add();
}

}
void add(){
Kid k = new Kid();
k.id = count;
if(count <= 0){
first = k;
last = k;
k.left = k;
k.right = k;
}else{
last.right = k;
k.left = last;
k.right = first;
first.left = k;
last = k;
}
count++;
}
void delete(Kid k){
if(count <= 0){
return;
}else if(count == 1){
last = first = null;
}else{
k.left.right = k.right;
k.right.left = k.left;
if(k == first){
first = k.right;
}else if(k == last){
last = k.left;
}
}
count--;
}
}