如何实现返回二叉树中存储着偶数的分支节点数

Question

Java中如何实现返回二叉树中存储着偶数的分支节点数？图中的代码又应该如何补全？

Answer 1

//假设IntTreeNode的结构如下
class IntTreeNode {
    int val;//值
    IntTreeNode left;//左子树
    IntTreeNode right;//右子树

    public IntTreeNode(int val) {
        this.val = val;
    }
}

//补全后的代码
private int countEvenBranches(IntTreeNode root) {
        if (root == null || root.left == null && root.right == null && root.val % 2 != 0) {
            return 0;
        } else {
            int result = 0;
            if (root.val % 2 == 0) {
                result = 1;
            }
            return result + countEvenBranches(root.left) + countEvenBranches(root.right);
        }
    }