package Solution;public class No27ConvertBinarySearchTreeToLinkedList {static class BinaryTreeNode {int value;BinaryTreeNode left;BinaryTreeNode right;public BinaryTreeNode() {}public BinaryTreeNode(int value, BinaryTreeNode left,BinaryTreeNode right) {this.value = value;this.left = left;this.right = right;}}public static BinaryTreeNode convert(BinaryTreeNode root) {BinaryTreeNode lastNodeInList = null;lastNodeInList = convertToNode(root, lastNodeInList);BinaryTreeNode head = lastNodeInList;// 从尾节点返回头结点while (head != null && head.left != null) {head = head.left;}printList(head);return head;}private static BinaryTreeNode convertToNode(BinaryTreeNode node,BinaryTreeNode lastNodeInList) {if (node == null)return null;BinaryTreeNode current = node;// 递归的处理左子树if (current.left != null)lastNodeInList = convertToNode(current.left, lastNodeInList);// 使链表中的最后一个结点指向左子树的最小的节点current.left = lastNodeInList;// 链表中的最后一个结点指向当前节点，当前节点就成了链表中的最后一个结点if (lastNodeInList != null)lastNodeInList.right = current;lastNodeInList = current;// 递归转换右子树if (current.right != null)lastNodeInList = convertToNode(current.right, lastNodeInList);return lastNodeInList;}public static void printList(BinaryTreeNode head) {while (head != null) {System.out.print(head.value + ",");head = head.right;}}// 中序遍历二叉树public static void printTree(BinaryTreeNode root) {if (root != null) {printTree(root.left);System.out.print(root.value + ",");printTree(root.right);}}public static void main(String[] args) {BinaryTreeNode node1 = new BinaryTreeNode();BinaryTreeNode node2 = new BinaryTreeNode();BinaryTreeNode node3 = new BinaryTreeNode();BinaryTreeNode node4 = new BinaryTreeNode();BinaryTreeNode node5 = new BinaryTreeNode();BinaryTreeNode node6 = new BinaryTreeNode();BinaryTreeNode node7 = new BinaryTreeNode();node7.value = 16;node6.value = 12;node5.value = 14;node5.left = node6;node5.right = node7;node3.value = 4;node4.value = 8;node2.value = 6;node2.left = node3;node2.right = node4;node1.value = 10;node1.left = node2;node1.right = node5;printTree(node1);System.out.println();System.out.println("=============打印链表================");convert(node1);}
}