java 实现栈数据结构

[java]代码库

import java.util.ArrayList;

public class ArrayListAsStack {
	ArrayList stack = new ArrayList();

	public ArrayListAsStack(int n) {
		stack.ensureCapacity(n);
	}

	public void push(Object o1) {
		stack.add(o1);
	}

	public Object pop() {
		return stack.remove(stack.size() - 1);
	}

	public Object topEle() {
		return stack.get(stack.size() - 1);
	}

	public boolean isEmpty() {

		return stack.isEmpty();
	}

	public void clean() {
		stack.clear();
	}
}