求二又树的叶子结点的个数,并打印输出所有叶子结点.

Question

怎么输出所有叶子结点。

Answer 1

public class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;
    TreeNode(int x) {
        val = x;
    }
    public static void main(String[] args) {
        Solution tree = new Solution();
        TreeNode root = new TreeNode(3);
        root.left = new TreeNode(9);
        root.right = new TreeNode(20);
        root.right.left = new TreeNode(15);
        root.right.right = new TreeNode(7);
        System.out.println("叶子节点总数："+tree.getLeafCount(root));
    }
}
class Solution {
    public int getLeafCount(TreeNode root) {
        if (root == null) {
            return 0;
        }
        if (root.left == null && root.right == null) {
            // 输出叶子节点
            System.out.println("叶子节点:" + root.val);
            return 1;
        }
        return getLeafCount(root.left) + getLeafCount(root.right);
    }
}