Merge pull request gzc426#308 from MMzhe/patch-10

gzc426 · web-flow · commit dd5425216906 · 2018-12-04T19:09:57.000+08:00
Create sourcema.md
diff --git a/2018.12.05-leetcode102/sourcema.md b/2018.12.05-leetcode102/sourcema.md
@@ -0,0 +1,31 @@
+# LeetCode 102
+    /**
+     * 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>> levelOrder(TreeNode root) {
+             List<List<Integer>> lists = new ArrayList<>();
+            if (root == null) {
+                return lists;
+            }
+            dfs(lists, root, 0);
+            return lists;
+        }
+        private static void dfs(List<List<Integer>> lists, TreeNode root, int level) {
+            if (root == null) {
+                return;
+            }
+            if (lists.size() < level + 1) {
+                lists.add(new ArrayList<Integer>());
+            }
+            lists.get(level).add(root.val);
+            dfs(lists,root.left,level+1);
+            dfs(lists,root.right,level+1);
+        }
+    }
