给予一颗二叉树,返回其树的深度。 最大深度是从根节点到最远叶节点的最长路径上的节点数。
叶子是没有子节点的节点。
例 :
给予树:
3
/ \
9 20
/ \
15 7
返回深度 3.
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
class Solution {
public int maxDepth(TreeNode root) {
return getMaxDepth(root, 0);
}
public int getMaxDepth(TreeNode node, int depth) {
if (node == null) {
return depth;
}
depth++;
int leftDepth = getMaxDepth(node.left, depth);
int rightDepth = getMaxDepth(node.right, depth);
return depth = leftDepth > rightDepth ? leftDepth : rightDepth;
}
}
Runtime: 0 ms, faster than 100.00% of Java online submissions for Maximum Depth of Binary Tree. Memory Usage: 38.1 MB, less than 49.96% of Java online submissions for Maximum Depth of Binary Tree.