{
  "type": "code_options",
  "author": "https://github.com/begeekmyfriend/leetcode",
  "source": "solution.md",
  "exercise_id": "458f6358d7514fb6bcdfd7f9238c3d7a",
  "keywords": "位运算,数学,回溯",
  "title": "格雷编码",
  "desc": [
    {
      "content": "\n<p>格雷编码是一个二进制数字系统，在该系统中，两个连续的数值仅有一个位数的差异。</p>\n<p>给定一个代表编码总位数的非负整数<em> n</em>，打印其格雷编码序列。即使有多个不同答案，你也只需要返回其中一种。</p>\n<p>格雷编码序列必须以 0 开头。</p>\n<p>&nbsp;</p>\n<p><strong>示例 1:</strong></p>\n<pre><strong>输入:</strong>&nbsp;2<strong><br />输出:</strong>&nbsp;[0,1,3,2]<strong><br />解释:</strong>00 - 001 - 111 - 310 - 2对于给定的&nbsp;<em>n</em>，其格雷编码序列并不唯一。例如，[0,2,3,1]&nbsp;也是一个有效的格雷编码序列。00 - 010 - 211 - 301 - 1</pre>\n<p><strong>示例&nbsp;2:</strong></p>\n<pre><strong>输入:</strong>&nbsp;0<strong><br />输出:</strong>&nbsp;[0]<strong><br />解释:</strong> 我们定义格雷编码序列必须以 0 开头。给定编码总位数为 <em>n</em> 的格雷编码序列，其长度为 2<sup>n</sup>。当 <em>n</em> = 0 时，长度为 2<sup>0</sup> = 1。因此，当 <em>n</em> = 0 时，其格雷编码序列为 [0]。</pre>",
      "language": "markdown"
    }
  ],
  "answer": [
    {
      "content": "",
      "language": "cpp"
    }
  ],
  "prepared": [
    [
      {
        "content": "",
        "language": "cpp"
      }
    ],
    [
      {
        "content": "",
        "language": "cpp"
      }
    ],
    [
      {
        "content": "",
        "language": "cpp"
      }
    ]
  ],
  "template": {
    "content": "#include <stdio.h>\n#include <stdlib.h>\nint *grayCode(int n, int *returnSize)\n{\n\tif (n < 0)\n\t{\n\t\treturn NULL;\n\t}\n\tint i, count = 1 << n;\n\tint *codes = malloc(count * sizeof(int));\n\tfor (i = 0; i < count; i++)\n\t{\n\t\tcodes[i] = (i >> 1) ^ i;\n\t}\n\t*returnSize = 1 << n;\n\treturn codes;\n}\nint main(int argc, char **argv)\n{\n\tif (argc != 2)\n\t{\n\t\tfprintf(stderr, \"Usage: ./test n\\n\");\n\t\texit(-1);\n\t}\n\tint i, count;\n\tint *list = grayCode(atoi(argv[1]), &count);\n\tfor (i = 0; i < count; i++)\n\t{\n\t\tprintf(\"%d \", list[i]);\n\t}\n\tprintf(\"\\n\");\n\treturn 0;\n}",
    "language": "cpp"
  },
  "node_id": "dailycode-5a4d869e768940439c9c3f0672b4f188",
  "license": "csdn.net",
  "created_at": 1637894158,
  "topic_link": "https://bbs.csdn.net/topics/600470797"
}