add problem leetcode 431

src/class07_11/Code03_EncodeNaryTreeToBinaryTree.java

@@ -0,0 +1,86 @@
+package class07_11;
+
+import java.util.ArrayList;
+import java.util.List;
+
+// 本题测试链接：https://leetcode.com/problems/encode-n-ary-tree-to-binary-tree
+public class Code03_EncodeNaryTreeToBinaryTree {
+
+	// 提交时不要提交这个类
+	public static class Node {
+		public int val;
+		public List<Node> children;
+
+		public Node() {
+		}
+
+		public Node(int _val) {
+			val = _val;
+		}
+
+		public Node(int _val, List<Node> _children) {
+			val = _val;
+			children = _children;
+		}
+	};
+
+	// 提交时不要提交这个类
+	public static class TreeNode {
+		int val;
+		TreeNode left;
+		TreeNode right;
+
+		TreeNode(int x) {
+			val = x;
+		}
+	}
+
+	// 只提交这个类即可
+	class Codec {
+		// Encodes an n-ary tree to a binary tree.
+		public TreeNode encode(Node root) {
+			if (root == null) {
+				return null;
+			}
+			TreeNode head = new TreeNode(root.val);
+			head.left = en(root.children);
+			return head;
+		}
+
+		private TreeNode en(List<Node> children) {
+			TreeNode head = null;
+			TreeNode cur = null;
+			for (Node child : children) {
+				TreeNode tNode = new TreeNode(child.val);
+				if (head == null) {
+					head = tNode;
+				} else {
+					cur.right = tNode;
+				}
+				cur = tNode;
+				cur.left = en(child.children);
+			}
+			return head;
+		}
+
+		// Decodes your binary tree to an n-ary tree.
+		public Node decode(TreeNode root) {
+			if (root == null) {
+				return null;
+			}
+			return new Node(root.val, de(root.left));
+		}
+
+		public List<Node> de(TreeNode root) {
+			List<Node> children = new ArrayList<>();
+			while (root != null) {
+				Node cur = new Node(root.val, de(root.left));
+				children.add(cur);
+				root = root.right;
+			}
+			return children;
+		}
+
+	}
+
+}

src/class07_11/Code04_PrintBinaryTree.java

@@ -1,6 +1,6 @@
 package class07_11;
 
-public class Code03_PrintBinaryTree {
+public class Code04_PrintBinaryTree {
 
 	public static class Node {
 		public int value;

src/class07_11/Code05_TreeMaxWidth.java

@@ -4,7 +4,7 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.Queue;
 
-public class Code04_TreeMaxWidth {
+public class Code05_TreeMaxWidth {
 
 	public static class Node {
 		public int value;

src/class07_11/Code06_SuccessorNode.java

@@ -1,6 +1,6 @@
 package class07_11;
 
-public class Code05_SuccessorNode {
+public class Code06_SuccessorNode {
 
 	public static class Node {
 		public int value;

src/class07_11/Code07_PaperFolding.java

@@ -1,6 +1,6 @@
 package class07_11;
 
-public class Code06_PaperFolding {
+public class Code07_PaperFolding {
 
 	public static void printAllFolds(int N) {
 		printProcess(1, N, true);