剑指Offer，按之字形顺序打印二叉树

zebinh · zebinh · commit 73aea59ae567 · 2020-01-14T21:52:13.000+08:00
diff --git a/swordoffer/BinaryTreeZhiPrintSolution.java b/swordoffer/BinaryTreeZhiPrintSolution.java
@@ -0,0 +1,54 @@
+import java.util.ArrayList;
+
+/**
+ * ��ָOffer����֮����˳���ӡ������
+ */
+
+ public class BinaryTreeZhiPrintSolution{
+
+    public ArrayList<ArrayList<Integer> > Print(TreeNode pRoot) {
+
+        ArrayList<ArrayList<Integer>> result = new ArrayList<>();
+
+        if (pRoot == null) {
+            return result;
+        }
+
+        int level = 1;
+        ArrayList<TreeNode> currentLevel = new ArrayList<>();
+        currentLevel.add(pRoot);
+        
+        while(currentLevel.size() != 0) {
+
+            ArrayList<TreeNode> tmp = new ArrayList<>();
+            ArrayList<Integer> valList = new ArrayList<>();
+
+            if (level % 2 == 1) {
+                
+                for (TreeNode t : currentLevel) {
+                    if (t.left != null) {
+                        tmp.add(0, t.left);
+                    }
+                    if(t.right != null) {
+                        tmp.add(0, t.right);
+                    }
+                    valList.add(t.val);
+                }
+            }else{
+                for (TreeNode t : currentLevel) {
+                    if (t.right != null) {
+                        tmp.add(0, t.right);
+                    }
+                    if(t.left != null) {
+                        tmp.add(0, t.left);
+                    }
+                    valList.add(t.val);
+                }
+            }
+            level++;
+            result.add(valList);
+            currentLevel = tmp;
+        }
+        return result;
+    }
+ }
