开始刷题 leetcode day8： Minimum Depth of Binary Tree

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.

Java:

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public int minDepth(TreeNode root) {
        if(root == null) return 0;
        if(root.left == null && root.right == null) return 1;
        else if (root.left ==  null)
        {
            return minDepth(root.right) + 1;
        }else if(root.right == null)
        {
            return minDepth(root.left) + 1;
        }else{
            return Math.min(minDepth(root.left) + 1, minDepth(root.right) + 1);
        }
        
    }
}