Here is my recursive code for finding the number of nodes at even depths in a Binary Search Tree. Do I need a separate base case for when depth == 0 (to account for the root node at depth 0, 0 is even number) or will the code below cover that? Thanks!

public int numEvenDepth(Node root) {

// tree created somehow here

int depth = 0;

return numEvenDepthHelper(root, depth);

}

public int numEvenDepthHelper(Node root, int depth) {

if(root == null)

return 0;

int left = numEvenDepthHelper(root.left, depth + 1);

int right = numEvenDepthHelper(root.right, depth + 1);

if(depth % 2 != 0)

return (left + right);

return (left+right+1);

}