实现一个函数,检查二叉树是否平衡,平衡的定义如下,对于树中的任意一个结点,其两颗子树的高度差不超过1。给定指向树根结点的指针TreeNode* root,请返回一个bool,代表这棵树是否平衡。
import java.util.*; /* public class TreeNode { int val = 0; TreeNode left = null; TreeNode right = null; public TreeNode(int val) { this.val = val; } }*/ public class Balance { public boolean isBalance(TreeNode root) { if(root == null){ return true; } int lHeight = treeHeight(root.left); int rHeight = treeHeight(root.right); if(lHeight - rHeight <= 1 && lHeight - rHeight >= -1){ return isBalance(root.left) && isBalance(root.right); } return false; } public int treeHeight(TreeNode root){ if(root == null){ return 0; } int lHeight = treeHeight(root.left); int rHeight = treeHeight(root.right); return lHeight > rHeight ? lHeight + 1 : rHeight + 1; } }