Create TheRocket.md

Jerring · web-flow · commit 117681f0c6aa · 2018-12-06T19:12:29.000+08:00
diff --git a/2018.12.06-leetcode103/TheRocket.md b/2018.12.06-leetcode103/TheRocket.md
@@ -0,0 +1,42 @@
+```java
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+    public List<List<Integer>> zigzagLevelOrder(TreeNode root) {
+        List<List<Integer>> res = new LinkedList<>();
+        Queue<TreeNode> queue = new LinkedList<>();
+        if (root != null) {
+            queue.offer(root);
+        }
+        boolean leftToRight = true;
+        while (!queue.isEmpty()) {
+            int size = queue.size();
+            LinkedList<Integer> level = new LinkedList<>();
+            while (size-- != 0) {
+                TreeNode node = queue.poll();
+                if (leftToRight) {
+                    level.offerLast(node.val); 
+                } else {
+                    level.offerFirst(node.val); 
+                }
+                if (node.left != null) {
+                    queue.offer(node.left);
+                }
+                if (node.right != null) {
+                    queue.offer(node.right);
+                }
+            }
+            res.add(level);
+            leftToRight = !leftToRight;
+        }
+        return res;
+    }
+}
+```
