package Cap1;
import java.util.Iterator;
import edu.princeton.cs.introcs.StdOut;
public class ResizingArrayDeque<Item> implements Iterable<Item> {
private Item[] a = (Item[]) new Object[1];
private int N = 0;
public boolean isEmpty(){ return N == 0; }
public int size(){ return N; }
private void resize(int length){
Item[] temp = (Item[]) new Object[length];
for(int i=0;i<N;i++){
temp[i] = a[i];
}
a = temp;
}
public void pushLeft(Item item){
if(N == a.length) resize(2*a.length);
for(int i=N-1;i>=0;i--){
a[i+1] = a[i];
}
a[0] = item;
N ++ ;
}
public void pushRight(Item item){
if(N == a.length) resize(2*a.length);
a[N++] = item;
}
public Item popLeft(){
if(isEmpty()) return null;
Item item = a[0];
for(int i=0;i<N-1;i++){
a[i] = a[i+1];
}
a[--N]=null;
if(N <= a.length/4) resize(a.length/2);
return item;
}
public Item popRight(){
if(isEmpty()) return null;
Item item = a[--N];
a[N] = null;
if(N <= a.length/4) resize(a.length/2);
return item;
}
@Override
public Iterator<Item> iterator() {
// TODO Auto-generated method stub
return new ResizingArrayDequeIterator();
}
private class ResizingArrayDequeIterator implements Iterator<Item>{
private int cur = 0;
@Override
public boolean hasNext() {
// TODO Auto-generated method stub
return cur != N;
}
@Override
public Item next() {
// TODO Auto-generated method stub
return a[cur++];
}
@Override
public void remove() {
// TODO Auto-generated method stub
}
}
public static void main(String[] args) {
ResizingArrayDeque<Integer> r = new ResizingArrayDeque<Integer>();
for(int i=0;i<10;i++){
r.pushLeft(i);
r.pushRight(i);
}
for(int i=0;i<10;i++){
r.popLeft();
}
for(Integer i : r)
StdOut.println(i);
}
}
算法 第四版 1.3.33 ResizingArrayDeque
最新推荐文章于 2020-02-28 19:59:09 发布