{
   "question_id": 69,
   "question_title": "x 的平方根",
   "difficulty": "简单",
   "question_content": "<p>实现&nbsp;<code>int sqrt(int x)</code>&nbsp;函数。</p>\n<p>计算并返回&nbsp;<em>x</em>&nbsp;的平方根，其中&nbsp;<em>x </em>是非负整数。</p>\n<p>由于返回类型是整数，结果只保留整数的部分，小数部分将被舍去。</p>\n<p><strong>示例 1:</strong></p>\n<pre><strong>输入:</strong> 4<strong><br />输出:</strong> 2</pre>\n<p><strong>示例 2:</strong></p>\n<pre><strong>输入:</strong> 8<strong><br />输出:</strong> 2<strong><br />说明:</strong> 8 的平方根是 2.82842..., 由于返回类型是整数，小数部分将被舍去。</pre>",
   "topic_link": "https://bbs.csdn.net/topics/600470124",
   "cpp": "#include <bits/stdc++.h>\nusing namespace std;\nclass Solution\n{\npublic:\n\tint mySqrt(int x)\n\t{\n\t\tif (x == 0)\n\t\t{\n\t\t\treturn 0;\n\t\t}\n\t\tunsigned int lo = 1, hi = x;\n\t\tunsigned int mid = (lo + hi) / 2;\n\t\tfor (;;)\n\t\t{\n\t\t\tif (mid > x / mid)\n\t\t\t{\n\t\t\t\thi = mid;\n\t\t\t}\n\t\t\telse\n\t\t\t{\n\t\t\t\tif (mid + 1 > x / (mid + 1))\n\t\t\t\t{\n\t\t\t\t\tbreak;\n\t\t\t\t}\n\t\t\t\telse\n\t\t\t\t{\n\t\t\t\t\tlo = mid;\n\t\t\t\t}\n\t\t\t}\n\t\t\tmid = (lo + hi) / 2;\n\t\t}\n\t\treturn mid;\n\t}\n};",
   "java": "class Solution {\n\tpublic int mySqrt(int x) {\n\t\tint left = 0, right = 46340;\n\t\twhile (left < right) {\n\t\t\tint mid = (left + right) / 2;\n\t\t\tif (mid * mid < x)\n\t\t\t\tleft = mid + 1;\n\t\t\telse if (mid * mid > x)\n\t\t\t\tif ((mid - 1) * (mid - 1) <= x)\n\t\t\t\t\treturn mid - 1;\n\t\t\t\telse\n\t\t\t\t\tright = mid - 1;\n\t\t\telse\n\t\t\t\treturn mid;\n\t\t}\n\t\tif (left * left > x)\n\t\t\treturn left - 1;\n\t\treturn left;\n\t}\n}\n",
   "js": "",
   "python": "class Solution:\n\tdef mySqrt(self, x):\n\t\tif x == 0:\n\t\t\treturn 0\n\t\tif x < 4:\n\t\t\treturn 1\n\t\tres = 2 * self.mySqrt(x / 4)\n\t\tif (res + 1) * (res + 1) <= x and (res + 1) * (res + 1) >= 0:\n\t\t\treturn res + 1\n\t\treturn  res\n# %%\ns = Solution()\nprint(s.mySqrt(4))",
   "status": 1,
   "keywords": "数学,二分查找",
   "license": {
      "cpp": "https://github.com/begeekmyfriend/leetcode",
      "python": "https://github.com/qiyuangong/leetcode",
      "java": "https://github.com/zhangyu345293721/leetcode"
   },
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