二刷89

Author: diguage

docs/0089-gray-code.adoc

@@ -55,53 +55,33 @@ image::images/0089-3.png[{image_attr}]
 
 这个题的解法跟 xref:0338-counting-bits.adoc[338. Counting Bits] 有异曲同工之妙！
 
-== 参考资料
-
-. https://leetcode-cn.com/problems/gray-code/solution/gray-code-jing-xiang-fan-she-fa-by-jyd/[Gray Code （镜像反射法，图解） - 格雷编码 - 力扣（LeetCode）^]
-. https://en.wikipedia.org/wiki/Gray_code[Gray code - Wikipedia^]
-. http://mathworld.wolfram.com/GrayCode.html[Gray Code -- from Wolfram MathWorld^]
-
-
-The gray code is a binary numeral system where two successive values differ in only one bit.
-
-Given a non-negative integer _n_ representing the total number of bits in the code, print the sequence of gray code. A gray code sequence must begin with 0.
-
-*Example 1:*
 
-[subs="verbatim,quotes,macros"]
+[[src-0089]]
+[tabs]
+====
+一刷::
++
+--
+[{java_src_attr}]
 ----
-*Input:* 2
-*Output:* `[0,1,3,2]`
-*Explanation:*
-00 - 0
-01 - 1
-11 - 3
-10 - 2
-
-For a given _n_, a gray code sequence may not be uniquely defined.
-For example, [0,2,3,1] is also a valid gray code sequence.
-
-00 - 0
-10 - 2
-11 - 3
-01 - 1
+include::{sourcedir}/_0089_GrayCode.java[tag=answer]
 ----
+--
 
-*Example 2:*
-
-[subs="verbatim,quotes,macros"]
+二刷::
++
+--
+[{java_src_attr}]
 ----
-*Input:* 0
-*Output:* `[0]
-*Explanation:* We define the gray code sequence to begin with 0.
-             A gray code sequence of _n_ has size = 2^n^, which for _n_ = 0 the size is 2^0^ = 1.
-             Therefore, for _n_ = 0 the gray code sequence is [0].`
+include::{sourcedir}/_0089_GrayCode_2.java[tag=answer]
 ----
+--
+====
 
+== 参考资料
+
+. https://leetcode.cn/problems/gray-code/solutions/13637/gray-code-jing-xiang-fan-she-fa-by-jyd/?envType=study-plan-v2&envId=selected-coding-interview[89. 格雷编码 - 清晰图解^]
+. https://en.wikipedia.org/wiki/Gray_code[Gray code - Wikipedia^]
+. http://mathworld.wolfram.com/GrayCode.html[Gray Code -- from Wolfram MathWorld^]
 
-[[src-0089]]
-[{java_src_attr}]
-----
-include::{sourcedir}/_0089_GrayCode.java[tag=answer]
-----
 

logbook/202406.adoc

@@ -660,6 +660,11 @@
 |{doc_base_url}/0371-sum-of-two-integers.adoc[题解]
 |❌位运算
 
+|{counter:codes}
+|{leetcode_base_url}/gray-code/[89. Gray Code^]
+|{doc_base_url}/0089-gray-code.adoc[题解]
+|❌位运算
+
 |===
 
 截止目前，本轮练习一共完成 {codes} 道题。

src/main/java/com/diguage/algo/leetcode/_0089_GrayCode.java

@@ -13,12 +13,15 @@
  * @since 2020-02-05 19:36
  */
 public class _0089_GrayCode {
-  // tag::answer[]
+    // tag::answer[]
     /**
      * Runtime: 0 ms, faster than 100.00% of Java online submissions for Gray Code.
      * Memory Usage: 37 MB, less than 8.00% of Java online submissions for Gray Code.
      *
      * Copy from: https://leetcode-cn.com/problems/gray-code/solution/gray-code-jing-xiang-fan-she-fa-by-jyd/[Gray Code （镜像反射法，图解） - 格雷编码 - 力扣（LeetCode）]
+     *
+     * @author D瓜哥 · https://www.diguage.com
+     * @since 2020-02-05 19:36
      */
     public List<Integer> grayCode(int n) {
         List<Integer> result = new ArrayList<>((int) Math.pow(2, n));

src/main/java/com/diguage/algo/leetcode/_0089_GrayCode_2.java

@@ -0,0 +1,25 @@
+package com.diguage.algo.leetcode;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class _0089_GrayCode_2 {
+  // tag::answer[]
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2024-09-16 20:43:16
+   */
+  public List<Integer> grayCode(int n) {
+    List<Integer> result = new ArrayList<>((int) Math.pow(2, n));
+    result.add(0);
+    int head = 1;
+    for (int i = 0; i < n; i++) {
+      for (int j = result.size() - 1; j >= 0; j--) {
+        result.add(head + result.get(j));
+      }
+      head <<= 1;
+    }
+    return result;
+  }
+  // end::answer[]
+}