二叉树平衡性检查

src/leecode/tree/BalanceTree.java

@@ -0,0 +1,29 @@
+package leecode.tree;
+
+/**
+ * 检查二叉树平衡性
+ */
+public class BalanceTree {
+    public static void main(String[] args) {
+        Integer[] integers = new Integer[]{1,2,2,3,3,null,null,4,4};
+        TreeNode root = TreeNode.parseTree(integers);
+        System.out.println(isBalanced(root));
+    }
+    public static boolean isBalanced(TreeNode root) {
+        if (root == null) return true;
+        int left = getDepth(root.left);
+        int right = getDepth(root.right);
+        if (Math.abs(left - right) >= 2) {
+            return false;
+        }
+        return isBalanced(root.left) && isBalanced(root.right);
+    }
+
+    public static int getDepth(TreeNode node){
+        if (node == null) {
+            return 0;
+        }
+        return Math.max(1 + getDepth(node.left),1 + getDepth(node.right));
+    }
+
+}