From a35c713322e813c3ffd5722d8bfa448e739e51b9 Mon Sep 17 00:00:00 2001
From: YuCheng Hu <yuchenghu@ossez.com>
Date: Tue, 25 Dec 2018 16:00:26 -0500
Subject: [PATCH] =?UTF-8?q?Kayak=20=E6=B7=BB=E5=8A=A0=E6=95=B0=E7=BB=84?=
 =?UTF-8?q?=E6=8E=92=E5=88=97=E7=AE=97=E6=B3=95?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../codebank/interview/KayakCountUpDown.java  | 58 +++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/main/java/com/ossez/codebank/interview/KayakCountUpDown.java

diff --git a/src/main/java/com/ossez/codebank/interview/KayakCountUpDown.java b/src/main/java/com/ossez/codebank/interview/KayakCountUpDown.java
new file mode 100644
index 0000000000..8b696881a3
--- /dev/null
+++ b/src/main/java/com/ossez/codebank/interview/KayakCountUpDown.java
@@ -0,0 +1,58 @@
+package com.ossez.codebank.interview;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 
+ * @author YuCheng
+ *
+ */
+public class KayakCountUpDown {
+
+	static int minNumber = 0;
+	static int maxNumber = 0;
+	int tmpN = 0;
+	List<Integer> retList = new ArrayList<Integer>();
+
+	public List<Integer> countUp(int start, int end) {
+		maxNumber = end;
+		tmpN = start;
+		moveUp(0);
+		retList.add(end);
+		return retList;
+
+	}
+
+	public List<Integer> countUpDown(int start, int end) {
+		minNumber = start;
+		maxNumber = end;
+		tmpN = start;
+		
+		moveUp(0);
+		retList.add(end);
+		
+		moveDown(1);
+		return retList;
+	
+	}
+
+	private void moveUp(int n) {
+		retList.add(tmpN);
+		tmpN++;
+		if (tmpN != maxNumber) {
+			moveUp(tmpN + 1);
+		}
+
+	}
+
+	private void moveDown(int n) {
+		tmpN = (maxNumber - n );
+		retList.add(tmpN);
+
+		if (tmpN != minNumber) {
+			moveDown(n + 1);
+		}
+	}
+
+}