The latest articles on DEV Community by ym z (@ym_z_a211847c2518bf442268). https://dev.to/ym_z_a211847c2518bf442268 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3947410%2F1fb08164-e007-4845-8590-e569365b0237.png https://dev.to/ym_z_a211847c2518bf442268 en ym z Sat, 23 May 2026 09:18:43 +0000 https://dev.to/ym_z_a211847c2518bf442268/javamian-shi-hashmapbi-kao-ti-5fen-zhong-su-tong-264f https://dev.to/ym_z_a211847c2518bf442268/javamian-shi-hashmapbi-kao-ti-5fen-zhong-su-tong-264f <h2> HashMap底层结构 </h2> <div class="highlight js-code-highlight"> <pre class="highlight plaintext"><code>数组 + 链表 + 红黑树 默认容量16，负载因子0.75 链表&gt;8且数组≥64 → 转红黑树 </code></pre> </div> <h2> put流程 </h2> <ol> <li>计算hash：<code>key.hashCode() ^ (h &gt;&gt;&gt; 16)</code>（高低位混合）</li> <li>定位桶：<code>(n-1) &amp; hash</code>（取模优化）</li> <li>桶空→直接放；有值→尾插；&gt;8→红黑树</li> <li>size &gt; threshold → resize()扩容</li> </ol> <h2> 面试被追问 </h2> <p><strong>"为什么用红黑树不用AVL？"</strong></p> <p>红黑树插入旋转少，HashMap高频写场景更优。</p> <p><strong>"1.7和1.8区别？"</strong></p> <div class="table-wrapper-paragraph"><table> <thead> <tr> <th>1.7</th> <th>1.8</th> </tr> </thead> <tbody> <tr> <td>头插法</td> <td>尾插法</td> </tr> <tr> <td>数组+链表</td> <td>+红黑树</td> </tr> <tr> <td>扩容rehash</td> <td>高位运算</td> </tr> <tr> <td>死循环</td> <td>安全</td> </tr> </tbody> </table></div> <p>👉 更多面试题：<a href="https://Abyte-zym.github.io/arsenal" rel="noopener noreferrer">https://Abyte-zym.github.io/arsenal</a></p> java tutorial programming ym z Sat, 23 May 2026 09:18:14 +0000 https://dev.to/ym_z_a211847c2518bf442268/javashi-xi-hai-tou-gong-lue-3tian-300ge-gou-tong-wo-shi-zen-yao-na-dao-mian-shi-de-38gh https://dev.to/ym_z_a211847c2518bf442268/javashi-xi-hai-tou-gong-lue-3tian-300ge-gou-tong-wo-shi-zen-yao-na-dao-mian-shi-de-38gh <h2> 我的背景 </h2> <p>长春理工大学（双非），软件工程，2026届。</p> <h2> 投递数据 </h2> <ul> <li>BOSS直聘：329个沟通</li> <li>10+ HR主动联系</li> <li>拼多多/快手/亚信/Strikingly/泛微 全部拿到面试机会</li> </ul> <h2> 我的招呼语模板 </h2> <blockquote> <p>XX大学软件工程应届。Spring Boot+MyBatis实战，项目经验丰富。6月底到岗。</p> </blockquote> <p><strong>30字黄金长度。</strong> HR只看3秒，关键词要放在最前面。</p> <h2> 平台分配 </h2> <div class="table-wrapper-paragraph"><table> <thead> <tr> <th>平台</th> <th>数量/天</th> <th>技巧</th> </tr> </thead> <tbody> <tr> <td>BOSS直聘</td> <td>120</td> <td>9-10点、14-15点黄金窗口</td> </tr> <tr> <td>实习僧</td> <td>50</td> <td>关键词"可转正""远程""日常实习"</td> </tr> <tr> <td>智联招聘</td> <td>50</td> <td>筛选"3小时内回复"标签</td> </tr> </tbody> </table></div> <h2> 免费工具 </h2> <p>我做的Java面试免费弹药库（简历生成器+题库+模拟器+段位测试）：</p> <p>👉 <a href="https://Abyte-zym.github.io/arsenal" rel="noopener noreferrer">https://Abyte-zym.github.io/arsenal</a></p> java career jobsearch beginners