?? stackarray.java
字號(hào):
package dsa.adt;
import dsa.adt.Stack;
import dsa.exception.StackEmptyException;
public class StackArray implements Stack {
private final int LEN = 4; //數(shù)組的默認(rèn)大小
private Object[] elements; //數(shù)據(jù)元素?cái)?shù)組
private int top; //棧頂指針
public StackArray() {
top = -1;
elements = new Object[LEN];
}
//返回堆棧的大小
public int getSize() {
return top+1;
}
//判斷堆棧是否為空
public boolean isEmpty() {
return top<0;
}
//數(shù)據(jù)元素e入棧
public void push(Object e) {
if (getSize()>=elements.length) expandSpace();
elements[++top] = e;
}
private void expandSpace(){
Object[] a = new Object[elements.length*2];
for (int i=0; i<elements.length; i++)
a[i] = elements[i];
elements = a;
}
//棧頂元素出棧
public Object pop() throws StackEmptyException {
if (getSize()<1)
throw new StackEmptyException("錯(cuò)誤,堆棧為空。");
Object obj = elements[top];
elements[top--] = null;
return obj;
}
//取棧頂元素
public Object peek() throws StackEmptyException {
if (getSize()<1)
throw new StackEmptyException("錯(cuò)誤,堆棧為空。");
return elements[top];
}
}
?? 快捷鍵說(shuō)明
復(fù)制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號(hào)
Ctrl + =
減小字號(hào)
Ctrl + -