{
   "question_id": 70,
   "question_title": "爬楼梯",
   "difficulty": "简单",
   "question_content": "<p>假设你正在爬楼梯。需要 <em>n</em>&nbsp;阶你才能到达楼顶。</p><p>每次你可以爬 1 或 2 个台阶。你有多少种不同的方法可以爬到楼顶呢？</p><p><strong>注意：</strong>给定 <em>n</em> 是一个正整数。</p><p><strong>示例 1：</strong></p><pre><strong>输入：</strong> 2<strong><br />输出：</strong> 2<strong><br />解释：</strong> 有两种方法可以爬到楼顶。1.  1 阶 + 1 阶2.  2 阶</pre><p><strong>示例 2：</strong></p><pre><strong>输入：</strong> 3<strong><br />输出：</strong> 3<strong><br />解释：</strong> 有三种方法可以爬到楼顶。1.  1 阶 + 1 阶 + 1 阶2.  1 阶 + 2 阶3.  2 阶 + 1 阶</pre>",
   "topic_link": "https://bbs.csdn.net/topics/600470125",
   "cpp": "#include <bits/stdc++.h>\nusing namespace std;\nclass Solution\n{\npublic:\n\tint climbStairs(int n)\n\t{\n\t\tint a = 1;\n\t\tint b = 2;\n\t\tint c = 0;\n\t\tfor (int i = 3; i <= n; i++)\n\t\t{\n\t\t\tc = a + b;\n\t\t\ta = b;\n\t\t\tb = c;\n\t\t}\n\t\treturn n == 1 ? a : (n == 2 ? b : c);\n\t}\n};",
   "java": "class Solution {\n\tpublic int climbStairs(int n) {\n\t\tint[] num = new int[n + 1];\n\t\tnum[0] = 1;\n\t\tnum[1] = 1;\n\t\tfor (int i = 2; i <= n; i++) {\n\t\t\tnum[i] = num[i - 1] + num[i - 2];\n\t\t}\n\t\treturn num[n];\n\t}\n}\n",
   "js": "",
   "python": "class Solution(object):\n\tdef climbStairs(self, n):\n\t\tif n <= 1:\n\t\t\treturn 1\n\t\tdp = [1] * 2\n\t\tfor i in range(2, n + 1):\n\t\t\tdp[1], dp[0] = dp[1] + dp[0], dp[1]\n\t\treturn dp[1]\n# %%\ns = Solution()\nprint(s.climbStairs(2))",
   "status": 1,
   "keywords": "记忆化搜索,数学,动态规划",
   "license": {
      "cpp": "https://github.com/begeekmyfriend/leetcode",
      "python": "https://github.com/qiyuangong/leetcode",
      "java": "https://github.com/zhangyu345293721/leetcode"
   },
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