modify code

Author: algorithmzuo

src/class12/Code04_IsFull.java

@@ -12,56 +12,68 @@ public Node(int data) {
 }
 }
 
+// 第一种方法
+// 收集整棵树的高度h，和节点数n
+// 只有满二叉树满足 : 2 ^ h - 1 == n
 public static boolean isFull1(Node head) {
 if (head == null) {
 return true;
 }
-int height = h(head);
-int nodes = n(head);
-return (1 << height) - 1 == nodes;
+Info1 all = process1(head);
+return (1 << all.height) - 1 == all.nodes;
 }
 
-public static int h(Node head) {
-if (head == null) {
-return 0;
+public static class Info1 {
+public int height;
+public int nodes;
+
+public Info1(int h, int n) {
+height = h;
+nodes = n;
 }
-return Math.max(h(head.left), h(head.right)) + 1;
 }
 
-public static int n(Node head) {
+public static Info1 process1(Node head) {
 if (head == null) {
-return 0;
+return new Info1(0, 0);
 }
-return n(head.left) + n(head.right) + 1;
+Info1 leftInfo = process1(head.left);
+Info1 rightInfo = process1(head.right);
+int height = Math.max(leftInfo.height, rightInfo.height) + 1;
+int nodes = leftInfo.nodes + rightInfo.nodes + 1;
+return new Info1(height, nodes);
 }
 
+// 第二种方法
+// 收集子树是否是满二叉树
+// 收集子树的高度
+// 左树满 && 右树满 && 左右树高度一样 -> 整棵树是满的
 public static boolean isFull2(Node head) {
 if (head == null) {
 return true;
 }
-Info all = process(head);
-return (1 << all.height) - 1 == all.nodes;
+return process2(head).isFull;
 }
 
-public static class Info {
+public static class Info2 {
+public boolean isFull;
 public int height;
-public int nodes;
 
-public Info(int h, int n) {
+public Info2(boolean f, int h) {
+isFull = f;
 height = h;
-nodes = n;
 }
 }
 
-public static Info process(Node head) {
-if (head == null) {
-return new Info(0, 0);
+public static Info2 process2(Node h) {
+if (h == null) {
+return new Info2(true, 0);
 }
-Info leftInfo = process(head.left);
-Info rightInfo = process(head.right);
+Info2 leftInfo = process2(h.left);
+Info2 rightInfo = process2(h.right);
+boolean isFull = leftInfo.isFull && rightInfo.isFull && leftInfo.height == rightInfo.height;
 int height = Math.max(leftInfo.height, rightInfo.height) + 1;
-int nodes = leftInfo.nodes + rightInfo.nodes + 1;
-return new Info(height, nodes);
+return new Info2(isFull, height);
 }
 
 // for test
@@ -84,13 +96,14 @@ public static void main(String[] args) {
 int maxLevel = 5;
 int maxValue = 100;
 int testTimes = 1000000;
+System.out.println("测试开始");
 for (int i = 0; i < testTimes; i++) {
 Node head = generateRandomBST(maxLevel, maxValue);
 if (isFull1(head) != isFull2(head)) {
-System.out.println("Oops!");
+System.out.println("出错了!");
 }
 }
-System.out.println("finish!");
+System.out.println("测试结束");
 }
 
 }