LeetCode 111 Minimum Depth of Binary Tree

题目描述

Given a binary tree, find its minimum depth.

The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.

分析

参考：LeetCode 104 Maximum Depth of Binary Tree

Minimum Depth的定义如下：

代码

[code]    public static int minDepth(TreeNode root) {

        if (root == null) {
            return 0;
        }

        if (root.left == null && root.right == null) {
            return 1;
        } else if (root.left != null && root.right == null) {
            return minDepth(root.left) + 1;
        } else if (root.left == null && root.right != null) {
            return minDepth(root.right) + 1;
        }

        return Math.min(minDepth(root.left), minDepth(root.right)) + 1;
    }