test

lgt · lgt · commit 8ecaf2a2d9a8 · 2017-02-26T19:35:43.000+08:00
diff --git a/group07/724319952/src/cn/fyl/first/Stack.java b/group07/724319952/src/cn/fyl/first/Stack.java
@@ -0,0 +1,39 @@
+package cn.fyl.first;
+
+public class Stack {
+
+	private ArrayList elementData = new ArrayList();
+	int last;
+
+	public void push(Object o) {
+		elementData.add(o);
+	}
+
+	public Object pop() {
+		return elementData.remove(last-1);
+	}
+
+	public Object peek() {
+		last = elementData.size()-1;
+		return elementData.get(last);
+	}
+
+	public boolean isEmpty() {
+		if(elementData.size() > 0)
+			return false;
+		else
+			return true;
+	}
+
+	public int size() {
+		return elementData.size();
+	}
+
+	public static void main(String[] args) {
+		Stack s = new Stack();
+		s.push(1);
+		s.push(2);
+		s.push(3);
+		System.out.println(s.peek());
+	}
+}
