Java数据结构系列之——树（6）：二叉树的层序遍历

package tree.binarytree;

import java.util.LinkedList;

/**
 * 层序遍历二叉树
 *
 * @author wl
 *
 */
public class PrintFromTopToBotton {
	public static void printfromtoptobotton(BiTreeNode root) {
		if (root == null) {
			return;
		}

		LinkedList<BiTreeNode> queue = new LinkedList<BiTreeNode>();
		queue.addLast(root);

		while (queue.size() != 0) {
			BiTreeNode current = queue.pollFirst();
			System.out.println(current.data);

			if (current.leftNode != null) {
				queue.addLast(current.leftNode);
			}

			if (current.rightNode != null) {
				queue.addLast(current.rightNode);
			}
		}
	}
}