[Leetcode 8] 104 Maximum Depth of Binary Tree

Problem:

Given a binary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

 

Analysis:

Recursion can solve it.

The time complexity is O(h).

 

Code:

/**
 * Definition for binary tree
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public int maxDepth(TreeNode root) {
        // Start typing your Java solution below
        // DO NOT write main() function
        return depth(root, 0);
    }
    
    private int depth(TreeNode t, int dep) {
        if (t == null) 
            return dep;
        else
            return max(depth(t.left, dep+1), depth(t.right, dep+1));
    }
    
    private int max (int a, int b) {
        return a>b?a:b;
    }
}

 

Attention: