Leetcode/java/111.minimum-depth-of-binary-tree.java at master · widmonstertony/Leetcode · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
/*
 * @lc app=leetcode id=111 lang=java
 *
 * [111] Minimum Depth of Binary Tree
 */

// @lc code=start
/**
 * 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 {
    public int minDepth(TreeNode root) {
        if (root == null) {
            return 0;
        }
        if (root.left == null || root.right == null) {
            return 1 + Math.max(minDepth(root.right), minDepth(root.left));
        }
        return Math.min(minDepth(root.left), minDepth(root.right)) + 1;
    }
}
// @lc code=end