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是否平衡二叉树

题目

给定一颗二叉树的头节点head，返回这颗二叉树是不是平衡二叉树

平衡二叉树就是这个树的所有子树和它自己，左右子树高度差不超过1

1. 递归
2. 先判断左子树是否平衡
3. 再判断右子树是否平衡
4. 再整体判断

代码

public class IsBalancedTree {public static class Node {public int val;public Node left;public Node right;public Node(int val) {this.val = val;}}public static class Info {public int height;public boolean balancedFlag;public Info(int height, boolean balancedFlag) {this.height = height;this.balancedFlag = balancedFlag;}}public static boolean isBalanced(Node head) {return balancedProcess(head).balancedFlag;}private static Info balancedProcess(Node head) {if (head == null) {return new Info(0, true);}Info leftInfo = balancedProcess(head.left);Info rightInfo = balancedProcess(head.right);int height = Math.max(leftInfo.height, rightInfo.height) + 1;boolean flag = leftInfo.balancedFlag && rightInfo.balancedFlag && Math.abs(leftInfo.height - rightInfo.height) <= 1;return new Info(height, flag);}// 测试public static void main(String[] args) {Node head = new Node(1);head.left = new Node(2);head.right = new Node(3);head.left.left = new Node(4);head.left.right = new Node(5);head.right.left = new Node(6);head.right.right = new Node(7);head.right.right.right = new Node(8);head.right.right.right.right = new Node(9);System.out.println(isBalanced(head));}
}

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💎总结

本文中若是有出现的错误请在评论区或者私信指出，我再进行改正优化，如果文章对你有所帮助，请给博主一个宝贵的三连，感谢大家😘！！！

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