111_Minimum Depth of Binary Tree

/*
111_Minimum Depth of Binary Tree
Runtime: 0 ms, faster than 100.00% of Java online submissions for Minimum Depth of Binary Tree.
Memory Usage: 39.5 MB, less than 68.82% of Java online submissions for Minimum Depth of Binary Tree.*/
class Solution {
    public int minDepth(TreeNode root) {
        if(root==null)
            return 0;
        
        if(root.left==null && root.right==null)
            return 1;
        
        if(root.left==null)
           return 1+minDepth(root.right);
        if(root.right==null)
            return 1+minDepth(root.left);
        
       
        return 1+Math.min(minDepth(root.left),minDepth(root.right));
        
        
    }
}