LeetCode 543. 数据结构->二叉树的直径(左子树高度加右子树高度
原题链接
简单
作者:
JustDoIt11
,
2023-10-31 12:35:00
,
所有人可见
,
阅读 41
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
class Solution {
int ans = 0;
public int diameterOfBinaryTree(TreeNode root) {
dfs(root);
return ans - 1;
}
public int dfs(TreeNode root) {
if (root == null) return 0;
int x = dfs(root.left);
int y = dfs(root.right);
ans = Math.max(ans, x + y + 1);
return Math.max(x, y) + 1;
}
}