[Leetcode] 111. 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.

/**
 * Definition for binary tree
 * 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;
        return getMin(root);
    }
    private int getMin(TreeNode root){
        if(root == null) return Integer.MAX_VALUE;
        if(root.left == null && root.right == null) return 1;
        return Math.min(getMin(root.left), getMin(root.right)) + 1;
    }
}