Related Topics: “树”: https://leetcode.com/tag/tree/ “深度优先搜索”: https://leetcode.com/tag/depth-first-search/ “广度优先搜索”: https://leetcode.com/tag/breadth-first-search/ “二叉树”: https://leetcode.com/tag/binary-tree/ Similar Questions: “平衡二叉树”: https://leetcode.com/problems/balanced-binary-tree/ “二叉树的最小深度”: https://leetcode.com/problems/minimum-depth-of-binary-tree/ “N 叉树的最大深度”: https://leetcode.com/problems/maximum-depth-of-n-ary-tree/
Problem: Link to heading
给定一个二叉树，找出其最大深度。
二叉树的深度为根节点到最远叶子节点的最长路径上的节点数。
说明: 叶子节点是指没有子节点的节点。
示例：
给定二叉树 [3,9,20,null,null,15,7]，
3
/ \
9 20
/ \
15 7
返回它的最大深度 3 。
Solution: Link to heading
https://programmercarl.com/0104.二叉树的最大深度.html#递归法
class Solution {
public:
int maxDepth(TreeNode* root) {
if(root == nullptr) return 0;
int leftDepth = maxDepth(root->left);
int rightDepth = maxDepth(root->right);
return max(leftDepth, rightDepth) + 1;
}
};