https://blog.allenwu233.com/zh/ Recent content on 逍遥乡：Allen's World Hugo -- 0.154.5 zh Sun, 07 Dec 2025 10:52:00 +0800 https://blog.allenwu233.com/zh/posts/temporal-experience-density/ Mon, 19 May 2025 00:00:00 +0000 https://blog.allenwu233.com/zh/posts/temporal-experience-density/ “深夜研究心理学” https://blog.allenwu233.com/zh/posts/cd-box/ Thu, 24 Apr 2025 00:00:00 +0000 https://blog.allenwu233.com/zh/posts/cd-box/ 车万碟佬的日常 https://blog.allenwu233.com/zh/posts/moon-walking/ Wed, 16 Apr 2025 00:00:00 +0000 https://blog.allenwu233.com/zh/posts/moon-walking/ 大晚上的诗兴大发 https://blog.allenwu233.com/zh/posts/peel-an-orange/ Mon, 14 Apr 2025 00:00:00 +0000 https://blog.allenwu233.com/zh/posts/peel-an-orange/ 小病一场，剥一个橘子，觉得日子也不坏 https://blog.allenwu233.com/zh/posts/hugo-papermod/ Tue, 08 Apr 2025 21:05:44 +0800 https://blog.allenwu233.com/zh/posts/hugo-papermod/ 时隔一年的回归 https://blog.allenwu233.com/zh/posts/redmi-note-12-trubo-flash/ Tue, 26 Mar 2024 20:32:38 +0800 https://blog.allenwu233.com/zh/posts/redmi-note-12-trubo-flash/ 生命在于折腾 https://blog.allenwu233.com/zh/posts/nowcoder-k-subdivision/ Tue, 18 Jul 2023 15:16:44 +0800 https://blog.allenwu233.com/zh/posts/nowcoder-k-subdivision/ 基础的BFS https://blog.allenwu233.com/zh/posts/ritual-sense-of-life/ Tue, 27 Jun 2023 10:37:07 +0800 https://blog.allenwu233.com/zh/posts/ritual-sense-of-life/ 人生得意须尽欢，莫使金樽空对月 https://blog.allenwu233.com/zh/posts/contest-1833-d/ Thu, 25 May 2023 21:56:26 +0800 https://blog.allenwu233.com/zh/posts/contest-1833-d/ <h2 id="题目">题目</h2> <p><a href="https://codeforces.com/contest/1833/problem/D">D. Flipper</a></p> <p>题意：给出一个 $ n $ 排列<code>p[]</code>，选择一个区间<code>[l, r]</code> (l &lt;= r)，构造一个新的排列：<code>a[r+1 : ] + a[l : r].reverse() + a[1 : l]</code> (在这里我用 Python 切片表示，即左闭右开区间)，求能构造出的字典序最大的排列</p> <h2 id="分析">分析</h2> <p>假设答案用 $ ans_i $ 表示</p> <p>初步分析，当 $ r = n $ 时，$ans_1 = r_{n}$，否则 $ans_1 = r_{n+1}$。为了保证字典序最大，我们需要选取尽可能大的 $ r $</p> <p>易知当 $ p_1 = n $ 时，$ r $ 应选取 $ n-1 $，否则选取 $ n $</p> <p>确定 $ r $ 后再来看 $ l $，这里有个技巧：先输出<code>a[r+1 : ] + a[r]</code>，再从<code>a[r-1]</code>开始往前遍历，只要 <code>a[i] &lt; a[1]</code>（说明如果 $ l $ 选 $ i $ 的话，操作之后字典序反而变小，所以 $ l $ 选 $ i+1 $），就马上输出 <code>a[1 : i+1]</code> (注意这里还是左闭右开区间)</p> https://blog.allenwu233.com/zh/posts/worldhello/ Wed, 24 May 2023 22:51:26 +0800 https://blog.allenwu233.com/zh/posts/worldhello/ 不仅仅是 Hello world https://blog.allenwu233.com/zh/posts/end-of-my-acm/ Wed, 17 May 2023 22:43:27 +0800 https://blog.allenwu233.com/zh/posts/end-of-my-acm/ 实迷途其未远，觉今是而昨非 https://blog.allenwu233.com/zh/posts/contest-1822/ Tue, 25 Apr 2023 15:59:32 +0800 https://blog.allenwu233.com/zh/posts/contest-1822/ 第一篇CF题解 https://blog.allenwu233.com/zh/posts/allen-dynamic-programming/ Mon, 13 Mar 2023 21:58:57 +0800 https://blog.allenwu233.com/zh/posts/allen-dynamic-programming/ 状态和状态转移方程 https://blog.allenwu233.com/zh/posts/allen-graph/ Sun, 26 Feb 2023 15:37:08 +0800 https://blog.allenwu233.com/zh/posts/allen-graph/ 比如......一笔画问题？ https://blog.allenwu233.com/zh/posts/8-nums/ Fri, 27 Jan 2023 15:47:55 +0800 https://blog.allenwu233.com/zh/posts/8-nums/ Hash与BFS https://blog.allenwu233.com/zh/posts/uva12166/ Thu, 12 Jan 2023 16:57:44 +0800 https://blog.allenwu233.com/zh/posts/uva12166/ 二叉树与天平 https://blog.allenwu233.com/zh/posts/uva1600/ Wed, 11 Jan 2023 12:30:00 +0800 https://blog.allenwu233.com/zh/posts/uva1600/ BFS求最短路的升级版 https://blog.allenwu233.com/zh/posts/uva439/ Mon, 09 Jan 2023 18:33:00 +0800 https://blog.allenwu233.com/zh/posts/uva439/ 来下国际象棋吧 https://blog.allenwu233.com/zh/posts/backtracking/ Sat, 03 Dec 2022 20:00:00 +0800 https://blog.allenwu233.com/zh/posts/backtracking/ 减少不必要的枚举 https://blog.allenwu233.com/zh/posts/little-reimu/ Fri, 25 Nov 2022 22:00:00 +0800 https://blog.allenwu233.com/zh/posts/little-reimu/ 观《东方幼灵梦》有感 https://blog.allenwu233.com/zh/posts/binary-tree/ Sun, 06 Nov 2022 22:00:00 +0800 https://blog.allenwu233.com/zh/posts/binary-tree/ 最近看什么都像二叉树（ https://blog.allenwu233.com/zh/posts/stack/ Sun, 30 Oct 2022 14:00:00 +0800 https://blog.allenwu233.com/zh/posts/stack/ 简单而又不简单 https://blog.allenwu233.com/zh/posts/greedy-algorithm/ Fri, 07 Oct 2022 00:00:00 +0000 https://blog.allenwu233.com/zh/posts/greedy-algorithm/ 这破题我写了三天.jpg https://blog.allenwu233.com/zh/posts/poly-newton/ Sun, 02 Oct 2022 00:00:00 +0000 https://blog.allenwu233.com/zh/posts/poly-newton/ Python 与数学的碰撞 https://blog.allenwu233.com/zh/posts/hanoi/ Sun, 11 Sep 2022 00:00:00 +0000 https://blog.allenwu233.com/zh/posts/hanoi/ 与算法的邂逅 https://blog.allenwu233.com/zh/posts/hello-world/ Fri, 26 Aug 2022 00:00:00 +0000 https://blog.allenwu233.com/zh/posts/hello-world/ Allen的第一篇博客 https://blog.allenwu233.com/zh/about/ Fri, 26 Aug 2022 00:00:00 +0000 https://blog.allenwu233.com/zh/about/ 一般路过车万人 https://blog.allenwu233.com/zh/links/ Mon, 01 Jan 0001 00:00:00 +0000 https://blog.allenwu233.com/zh/links/ <ul> <li><a href="https://blog.linioi.com">清絮</a> <ul> <li>人生如逆旅，我亦是行人</li> </ul> </li> <li><a href="https://blog.lilydjwg.me/">lilydjwg 依云</a> <ul> <li>百合仙子，Arch Linux CN 社区管理者之一</li> </ul> </li> <li><a href="https://www.yunyitang.me/zh/">Yunyi&rsquo;s Blog</a> <ul> <li>Little squirrel Hopping around</li> </ul> </li> <li><a href="https://www.ruanyifeng.com/">阮一峰</a> <ul> <li>坚持更新网络日志，将博客精神体现得淋漓尽致</li> </ul> </li> <li><a href="https://pxyfcywl.netlify.app">彼岸花开</a> <ul> <li>欢迎！高洁而真诚的灵魂</li> </ul> </li> </ul> <h2 id="又一条新航线">又一条新航线</h2> <p>欢迎在评论区留下你的博客链接，最好按以下格式：</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-text" data-lang="text"><span class="line"><span class="cl">title: # 你的名字 </span></span><span class="line"><span class="cl">description: # 一句话个人或博客简介 </span></span><span class="line"><span class="cl">website: # 个人网站 </span></span><span class="line"><span class="cl">avatar: # 头像链接（可选） </span></span></code></pre></div><p>博主信息，请随意添加：</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-text" data-lang="text"><span class="line"><span class="cl">title: Allen Wu </span></span><span class="line"><span class="cl">description: 天地与我并生，而万物与我为一。 </span></span><span class="line"><span class="cl">website: https://blog.allenwu233.com </span></span><span class="line"><span class="cl">avatar: https://blog.allenwu233.com/img/avatar.png </span></span><span class="line"><span class="cl">favicon: https://blog.allenwu233.com/img/favicon/favicon-32x32.png </span></span></code></pre></div><p>🍻欢迎友好交流！不要吝啬你的友链！</p>