62,635
社区成员




public class TestStackOfIntegers{
public static void main(String[] args){
StackOfIntegers stack = new StackOfIntegers();
for(int i = 0; i < 10; i++)
stack.push(i);
while(!stack.empty())
System.out.print(stack.pop() + " ");
}
}
class StackOfIntegers{
private int[] elements;
private int size;
private static final int DEFAULT_CAPACITY = 16;
public StackOfIntegers(){
this(DEFAULT_CAPACITY);
}
public StackOfIntegers(int capacity){
elements = new int[capacity];
}
public void push(int value){
if(size >= elements.length){
int[] temp = new int[elements.length * 2];
System.arraycopy(elements, 0, temp, 0, elements.length);
elements = temp;
}
elements[size++] = value;
}
public int pop(){
return elements[--size];
}
public int peek(){
return elements[size - 1];
}
public boolean empty(){
return size == 0;
}
public int getSize(){
return size;
}
}
import java.util.LinkedList;
public class Stack<T>
{
private LinkedList<T> storage = new LinkedList<T>();
public void push(T v){storage.addFirst(v);}
public T peek(){return storage.getFirst();}
public T pop(){return storage.removeFirst();}
public boolean empty(){return storage.isEmpty();}
public String toString(){return storage.toString();}
}
public void push(int value){
if(size >= elements.length){
int[] temp = new int[elements.length * 2];
System.arraycopy(elements, 0, temp, 0, elements.length);
elements = temp;
}
elements[size++] = value;
}
这其实是ArrayList的底层实现罢了,你所定义的的类的底层是由一个数组来维护的,这个数组本身有一个默认的长度,当你向数组中添加元素时,先判断是否已达到原有数组的长度,如果达到,则在新建一个数组长度是原数组的两倍,然后将原数组中的元素拷贝到新数组中。对于你说的size的大小问题我认为是你存储元素的个数。
对于模仿Stack实现其实你可以用现成的ArrayList类或者LinkedList类,建议楼主看一下他们的源代码