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# 力扣题库（完整版）
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> 最后更新日期： **2022.05.02**
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> 最后更新日期： **2022.05.13**
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>
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> 使用脚本前请务必仔细完整阅读本 `README.md` 文件
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leetcode-cn/originData/count-number-of-texts.json
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<p>给你一个字符串 <code>num</code> ，表示一个大整数。如果一个整数满足下述所有条件，则认为该整数是一个 <strong>优质整数</strong> ：</p>
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<ul>
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<li>该整数是 <code>num</code> 的一个长度为 <code>3</code> 的 <strong>子字符串</strong> 。</li>
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<li>该整数由唯一一个数字重复 <code>3</code> 次组成。</li>
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</ul>
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<p>以字符串形式返回 <strong>最大的优质整数</strong> 。如果不存在满足要求的整数，则返回一个空字符串 <code>""</code> 。</p>
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<p><strong>注意：</strong></p>
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<ul>
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<li><strong>子字符串</strong> 是字符串中的一个连续字符序列。</li>
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<li><code>num</code> 或优质整数中可能存在 <strong>前导零</strong> 。</li>
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</ul>
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<p> </p>
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<p><strong>示例 1：</strong></p>
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<pre>
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<strong>输入：</strong>num = "6<em><strong>777</strong></em>133339"
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<strong>输出：</strong>"777"
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<strong>解释：</strong>num 中存在两个优质整数："777" 和 "333" 。
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"777" 是最大的那个，所以返回 "777" 。
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</pre>
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<p><strong>示例 2：</strong></p>
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<pre>
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<strong>输入：</strong>num = "23<em><strong>000</strong></em>19"
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<strong>输出：</strong>"000"
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<strong>解释：</strong>"000" 是唯一一个优质整数。
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</pre>
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<p><strong>示例 3：</strong></p>
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<pre>
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<strong>输入：</strong>num = "42352338"
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<strong>输出：</strong>""
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<strong>解释：</strong>不存在长度为 3 且仅由一个唯一数字组成的整数。因此，不存在优质整数。
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</pre>
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<p> </p>
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<p><strong>提示：</strong></p>
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<ul>
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<li><code>3 <= num.length <= 1000</code></li>
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<li><code>num</code> 仅由数字（<code>0</code> - <code>9</code>）组成</li>
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</ul>
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<p>一个括号字符串是一个 <strong>非空</strong> 且只包含 <code>'('</code> 和 <code>')'</code> 的字符串。如果下面 <strong>任意</strong> 条件为 <strong>真</strong> ，那么这个括号字符串就是 <strong>合法的</strong> 。</p>
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<ul>
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<li>字符串是 <code>()</code> 。</li>
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<li>字符串可以表示为 <code>AB</code>（<code>A</code> 连接 <code>B</code>），<code>A</code> 和 <code>B</code> 都是合法括号序列。</li>
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<li>字符串可以表示为 <code>(A)</code> ，其中 <code>A</code> 是合法括号序列。</li>
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</ul>
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<p>给你一个 <code>m x n</code> 的括号网格图矩阵 <code>grid</code> 。网格图中一个 <strong>合法括号路径</strong> 是满足以下所有条件的一条路径：</p>
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<ul>
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<li>路径开始于左上角格子 <code>(0, 0)</code> 。</li>
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<li>路径结束于右下角格子 <code>(m - 1, n - 1)</code> 。</li>
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<li>路径每次只会向 <strong>下</strong> 或者向 <strong>右</strong> 移动。</li>
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<li>路径经过的格子组成的括号字符串是<strong> 合法</strong> 的。</li>
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</ul>
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<p>如果网格图中存在一条 <strong>合法括号路径</strong> ，请返回 <code>true</code> ，否则返回 <code>false</code> 。</p>
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<p> </p>
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<p><strong>示例 1：</strong></p>
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<p><img alt="" src="https://assets.leetcode.com/uploads/2022/03/15/example1drawio.png" style="width: 521px; height: 300px;" /></p>
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<pre>
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<b>输入：</b>grid = [["(","(","("],[")","(",")"],["(","(",")"],["(","(",")"]]
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<b>输出：</b>true
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<b>解释：</b>上图展示了两条路径，它们都是合法括号字符串路径。
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第一条路径得到的合法字符串是 "()(())" 。
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第二条路径得到的合法字符串是 "((()))" 。
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注意可能有其他的合法括号字符串路径。
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</pre>
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<p><strong>示例 2：</strong></p>
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<p><img alt="" src="https://assets.leetcode.com/uploads/2022/03/15/example2drawio.png" style="width: 165px; height: 165px;" /></p>
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<pre>
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<b>输入：</b>grid = [[")",")"],["(","("]]
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<b>输出：</b>false
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<b>解释：</b>两条可行路径分别得到 "))(" 和 ")((" 。由于它们都不是合法括号字符串，我们返回 false 。
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</pre>
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<p> </p>
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<p><strong>提示：</strong></p>
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<ul>
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<li><code>m == grid.length</code></li>
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<li><code>n == grid[i].length</code></li>
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<li><code>1 <= m, n <= 100</code></li>
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<li><code>grid[i][j]</code> 要么是 <code>'('</code> ，要么是 <code>')'</code> 。</li>
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</ul>
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<p>给你一棵二叉树的根节点 <code>root</code> ，找出并返回满足要求的节点数，要求节点的值等于其 <strong>子树</strong> 中值的 <strong>平均值</strong> 。</p>
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<p><strong>注意：</strong></p>
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<ul>
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<li><code>n</code> 个元素的平均值可以由 <code>n</code> 个元素 <strong>求和</strong> 然后再除以 <code>n</code> ，并 <strong>向下舍入</strong> 到最近的整数。</li>
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<li><code>root</code> 的 <strong>子树</strong> 由 <code>root</code> 和它的所有后代组成。</li>
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</ul>
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<p> </p>
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<p><strong>示例 1：</strong></p>
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<img src="https://assets.leetcode.com/uploads/2022/03/15/image-20220315203925-1.png" style="width: 300px; height: 212px;">
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<pre><strong>输入：</strong>root = [4,8,5,0,1,null,6]
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<strong>输出：</strong>5
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<strong>解释：</strong>
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对值为 4 的节点：子树的平均值 (4 + 8 + 5 + 0 + 1 + 6) / 6 = 24 / 6 = 4 。
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对值为 5 的节点：子树的平均值 (5 + 6) / 2 = 11 / 2 = 5 。
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对值为 0 的节点：子树的平均值 0 / 1 = 0 。
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对值为 1 的节点：子树的平均值 1 / 1 = 1 。
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对值为 6 的节点：子树的平均值 6 / 1 = 6 。
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</pre>
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<p><strong>示例 2：</strong></p>
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<img src="https://assets.leetcode.com/uploads/2022/03/26/image-20220326133920-1.png" style="width: 80px; height: 76px;">
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<pre><strong>输入：</strong>root = [1]
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<strong>输出：</strong>1
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<strong>解释：</strong>对值为 1 的节点：子树的平均值 1 / 1 = 1。
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</pre>
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<p> </p>
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<p><strong>提示：</strong></p>
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<ul>
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<li>树中节点数目在范围 <code>[1, 1000]</code> 内</li>
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<li><code>0 <= Node.val <= 1000</code></li>
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</ul>
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<p>Alice 在给 Bob 用手机打字。数字到字母的 <strong>对应</strong> 如下图所示。</p>
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<p><img alt="" src="https://assets.leetcode.com/uploads/2022/03/15/1200px-telephone-keypad2svg.png" style="width: 200px; height: 162px;"></p>
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<p>为了 <strong>打出</strong> 一个字母，Alice 需要 <strong>按</strong> 对应字母 <code>i</code> 次，<code>i</code> 是该字母在这个按键上所处的位置。</p>
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<ul>
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<li>比方说，为了按出字母 <code>'s'</code> ，Alice 需要按 <code>'7'</code> 四次。类似的， Alice 需要按 <code>'5'</code> 两次得到字母 <code>'k'</code> 。</li>
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<li>注意，数字 <code>'0'</code> 和 <code>'1'</code> 不映射到任何字母，所以 Alice <strong>不</strong> 使用它们。</li>
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</ul>
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<p>但是，由于传输的错误，Bob 没有收到 Alice 打字的字母信息，反而收到了 <strong>按键的字符串信息</strong> 。</p>
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<ul>
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<li>比方说，Alice 发出的信息为 <code>"bob"</code> ，Bob 将收到字符串 <code>"2266622"</code> 。</li>
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</ul>
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<p>给你一个字符串 <code>pressedKeys</code> ，表示 Bob 收到的字符串，请你返回 Alice <strong>总共可能发出多少种文字信息</strong> 。</p>
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<p>由于答案可能很大，将它对 <code>10<sup>9</sup> + 7</code> <strong>取余</strong> 后返回。</p>
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<p> </p>
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<p><strong>示例 1：</strong></p>
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<pre><b>输入：</b>pressedKeys = "22233"
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<b>输出：</b>8
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<strong>解释：</strong>
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Alice 可能发出的文字信息包括：
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"aaadd", "abdd", "badd", "cdd", "aaae", "abe", "bae" 和 "ce" 。
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由于总共有 8 种可能的信息，所以我们返回 8 。
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</pre>
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<p><strong>示例 2：</strong></p>
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<pre><b>输入：</b>pressedKeys = "222222222222222222222222222222222222"
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<b>输出：</b>82876089
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<strong>解释：</strong>
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总共有 2082876103 种 Alice 可能发出的文字信息。
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由于我们需要将答案对 10<sup>9</sup> + 7 取余，所以我们返回 2082876103 % (10<sup>9</sup> + 7) = 82876089 。
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</pre>
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<p> </p>
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<p><strong>提示：</strong></p>
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<ul>
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<li><code>1 <= pressedKeys.length <= 10<sup>5</sup></code></li>
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<li><code>pressedKeys</code> 只包含数字 <code>'2'</code> 到 <code>'9'</code> 。</li>
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</ul>
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<p>You are given a string <code>num</code> representing a large integer. An integer is <strong>good</strong> if it meets the following conditions:</p>
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<ul>
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<li>It is a <strong>substring</strong> of <code>num</code> with length <code>3</code>.</li>
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<li>It consists of only one unique digit.</li>
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</ul>
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<p>Return <em>the <strong>maximum good </strong>integer as a <strong>string</strong> or an empty string </em><code>""</code><em> if no such integer exists</em>.</p>
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<p>Note:</p>
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<ul>
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<li>A <strong>substring</strong> is a contiguous sequence of characters within a string.</li>
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<li>There may be <strong>leading zeroes</strong> in <code>num</code> or a good integer.</li>
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</ul>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<pre>
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<strong>Input:</strong> num = "6<strong><u>777</u></strong>133339"
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<strong>Output:</strong> "777"
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<strong>Explanation:</strong> There are two distinct good integers: "777" and "333".
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"777" is the largest, so we return "777".
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</pre>
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<p><strong>Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> num = "23<strong><u>000</u></strong>19"
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<strong>Output:</strong> "000"
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<strong>Explanation:</strong> "000" is the only good integer.
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</pre>
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<p><strong>Example 3:</strong></p>
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<pre>
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<strong>Input:</strong> num = "42352338"
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<strong>Output:</strong> ""
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<strong>Explanation:</strong> No substring of length 3 consists of only one unique digit. Therefore, there are no good integers.
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li><code>3 <= num.length <= 1000</code></li>
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<li><code>num</code> only consists of digits.</li>
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</ul>
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<p>A parentheses string is a <strong>non-empty</strong> string consisting only of <code>'('</code> and <code>')'</code>. It is <strong>valid</strong> if <strong>any</strong> of the following conditions is <strong>true</strong>:</p>
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<ul>
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<li>It is <code>()</code>.</li>
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<li>It can be written as <code>AB</code> (<code>A</code> concatenated with <code>B</code>), where <code>A</code> and <code>B</code> are valid parentheses strings.</li>
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<li>It can be written as <code>(A)</code>, where <code>A</code> is a valid parentheses string.</li>
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</ul>
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<p>You are given an <code>m x n</code> matrix of parentheses <code>grid</code>. A <strong>valid parentheses string path</strong> in the grid is a path satisfying <strong>all</strong> of the following conditions:</p>
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<ul>
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<li>The path starts from the upper left cell <code>(0, 0)</code>.</li>
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<li>The path ends at the bottom-right cell <code>(m - 1, n - 1)</code>.</li>
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<li>The path only ever moves <strong>down</strong> or <strong>right</strong>.</li>
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<li>The resulting parentheses string formed by the path is <strong>valid</strong>.</li>
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</ul>
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<p>Return <code>true</code> <em>if there exists a <strong>valid parentheses string path</strong> in the grid.</em> Otherwise, return <code>false</code>.</p>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2022/03/15/example1drawio.png" style="width: 521px; height: 300px;" />
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<pre>
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<strong>Input:</strong> grid = [["(","(","("],[")","(",")"],["(","(",")"],["(","(",")"]]
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<strong>Output:</strong> true
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<strong>Explanation:</strong> The above diagram shows two possible paths that form valid parentheses strings.
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The first path shown results in the valid parentheses string "()(())".
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The second path shown results in the valid parentheses string "((()))".
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Note that there may be other valid parentheses string paths.
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</pre>
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<p><strong>Example 2:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2022/03/15/example2drawio.png" style="width: 165px; height: 165px;" />
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<pre>
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<strong>Input:</strong> grid = [[")",")"],["(","("]]
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<strong>Output:</strong> false
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<strong>Explanation:</strong> The two possible paths form the parentheses strings "))(" and ")((". Since neither of them are valid parentheses strings, we return false.
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li><code>m == grid.length</code></li>
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<li><code>n == grid[i].length</code></li>
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<li><code>1 <= m, n <= 100</code></li>
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<li><code>grid[i][j]</code> is either <code>'('</code> or <code>')'</code>.</li>
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</ul>
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<p>Given the <code>root</code> of a binary tree, return <em>the number of nodes where the value of the node is equal to the <strong>average</strong> of the values in its <strong>subtree</strong></em>.</p>
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<p><strong>Note:</strong></p>
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<ul>
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<li>The <strong>average</strong> of <code>n</code> elements is the <strong>sum</strong> of the <code>n</code> elements divided by <code>n</code> and <strong>rounded down</strong> to the nearest integer.</li>
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<li>A <strong>subtree</strong> of <code>root</code> is a tree consisting of <code>root</code> and all of its descendants.</li>
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</ul>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<img src="https://assets.leetcode.com/uploads/2022/03/15/image-20220315203925-1.png" style="width: 300px; height: 212px;" />
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<pre>
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<strong>Input:</strong> root = [4,8,5,0,1,null,6]
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<strong>Output:</strong> 5
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<strong>Explanation:</strong>
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For the node with value 4: The average of its subtree is (4 + 8 + 5 + 0 + 1 + 6) / 6 = 24 / 6 = 4.
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||||
For the node with value 5: The average of its subtree is (5 + 6) / 2 = 11 / 2 = 5.
|
||||
For the node with value 0: The average of its subtree is 0 / 1 = 0.
|
||||
For the node with value 1: The average of its subtree is 1 / 1 = 1.
|
||||
For the node with value 6: The average of its subtree is 6 / 1 = 6.
|
||||
</pre>
|
||||
|
||||
<p><strong>Example 2:</strong></p>
|
||||
<img src="https://assets.leetcode.com/uploads/2022/03/26/image-20220326133920-1.png" style="width: 80px; height: 76px;" />
|
||||
<pre>
|
||||
<strong>Input:</strong> root = [1]
|
||||
<strong>Output:</strong> 1
|
||||
<strong>Explanation:</strong> For the node with value 1: The average of its subtree is 1 / 1 = 1.
|
||||
</pre>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Constraints:</strong></p>
|
||||
|
||||
<ul>
|
||||
<li>The number of nodes in the tree is in the range <code>[1, 1000]</code>.</li>
|
||||
<li><code>0 <= Node.val <= 1000</code></li>
|
||||
</ul>
|
||||
@ -0,0 +1,48 @@
|
||||
<p>Alice is texting Bob using her phone. The <strong>mapping</strong> of digits to letters is shown in the figure below.</p>
|
||||
<img alt="" src="https://assets.leetcode.com/uploads/2022/03/15/1200px-telephone-keypad2svg.png" style="width: 200px; height: 162px;" />
|
||||
<p>In order to <strong>add</strong> a letter, Alice has to <strong>press</strong> the key of the corresponding digit <code>i</code> times, where <code>i</code> is the position of the letter in the key.</p>
|
||||
|
||||
<ul>
|
||||
<li>For example, to add the letter <code>'s'</code>, Alice has to press <code>'7'</code> four times. Similarly, to add the letter <code>'k'</code>, Alice has to press <code>'5'</code> twice.</li>
|
||||
<li>Note that the digits <code>'0'</code> and <code>'1'</code> do not map to any letters, so Alice <strong>does not</strong> use them.</li>
|
||||
</ul>
|
||||
|
||||
<p>However, due to an error in transmission, Bob did not receive Alice's text message but received a <strong>string of pressed keys</strong> instead.</p>
|
||||
|
||||
<ul>
|
||||
<li>For example, when Alice sent the message <code>"bob"</code>, Bob received the string <code>"2266622"</code>.</li>
|
||||
</ul>
|
||||
|
||||
<p>Given a string <code>pressedKeys</code> representing the string received by Bob, return <em>the <strong>total number of possible text messages</strong> Alice could have sent</em>.</p>
|
||||
|
||||
<p>Since the answer may be very large, return it <strong>modulo</strong> <code>10<sup>9</sup> + 7</code>.</p>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Example 1:</strong></p>
|
||||
|
||||
<pre>
|
||||
<strong>Input:</strong> pressedKeys = "22233"
|
||||
<strong>Output:</strong> 8
|
||||
<strong>Explanation:</strong>
|
||||
The possible text messages Alice could have sent are:
|
||||
"aaadd", "abdd", "badd", "cdd", "aaae", "abe", "bae", and "ce".
|
||||
Since there are 8 possible messages, we return 8.
|
||||
</pre>
|
||||
|
||||
<p><strong>Example 2:</strong></p>
|
||||
|
||||
<pre>
|
||||
<strong>Input:</strong> pressedKeys = "222222222222222222222222222222222222"
|
||||
<strong>Output:</strong> 82876089
|
||||
<strong>Explanation:</strong>
|
||||
There are 2082876103 possible text messages Alice could have sent.
|
||||
Since we need to return the answer modulo 10<sup>9</sup> + 7, we return 2082876103 % (10<sup>9</sup> + 7) = 82876089.
|
||||
</pre>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Constraints:</strong></p>
|
||||
|
||||
<ul>
|
||||
<li><code>1 <= pressedKeys.length <= 10<sup>5</sup></code></li>
|
||||
<li><code>pressedKeys</code> only consists of digits from <code>'2'</code> - <code>'9'</code>.</li>
|
||||
</ul>
|
||||
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155
leetcode/originData/count-nodes-equal-to-average-of-subtree.json
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155
leetcode/originData/count-nodes-equal-to-average-of-subtree.json
Normal file
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155
leetcode/originData/count-number-of-texts.json
Normal file
155
leetcode/originData/count-number-of-texts.json
Normal file
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155
leetcode/originData/largest-3-same-digit-number-in-string.json
Normal file
155
leetcode/originData/largest-3-same-digit-number-in-string.json
Normal file
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@ -0,0 +1,48 @@
|
||||
<p>A parentheses string is a <strong>non-empty</strong> string consisting only of <code>'('</code> and <code>')'</code>. It is <strong>valid</strong> if <strong>any</strong> of the following conditions is <strong>true</strong>:</p>
|
||||
|
||||
<ul>
|
||||
<li>It is <code>()</code>.</li>
|
||||
<li>It can be written as <code>AB</code> (<code>A</code> concatenated with <code>B</code>), where <code>A</code> and <code>B</code> are valid parentheses strings.</li>
|
||||
<li>It can be written as <code>(A)</code>, where <code>A</code> is a valid parentheses string.</li>
|
||||
</ul>
|
||||
|
||||
<p>You are given an <code>m x n</code> matrix of parentheses <code>grid</code>. A <strong>valid parentheses string path</strong> in the grid is a path satisfying <strong>all</strong> of the following conditions:</p>
|
||||
|
||||
<ul>
|
||||
<li>The path starts from the upper left cell <code>(0, 0)</code>.</li>
|
||||
<li>The path ends at the bottom-right cell <code>(m - 1, n - 1)</code>.</li>
|
||||
<li>The path only ever moves <strong>down</strong> or <strong>right</strong>.</li>
|
||||
<li>The resulting parentheses string formed by the path is <strong>valid</strong>.</li>
|
||||
</ul>
|
||||
|
||||
<p>Return <code>true</code> <em>if there exists a <strong>valid parentheses string path</strong> in the grid.</em> Otherwise, return <code>false</code>.</p>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Example 1:</strong></p>
|
||||
<img alt="" src="https://assets.leetcode.com/uploads/2022/03/15/example1drawio.png" style="width: 521px; height: 300px;" />
|
||||
<pre>
|
||||
<strong>Input:</strong> grid = [["(","(","("],[")","(",")"],["(","(",")"],["(","(",")"]]
|
||||
<strong>Output:</strong> true
|
||||
<strong>Explanation:</strong> The above diagram shows two possible paths that form valid parentheses strings.
|
||||
The first path shown results in the valid parentheses string "()(())".
|
||||
The second path shown results in the valid parentheses string "((()))".
|
||||
Note that there may be other valid parentheses string paths.
|
||||
</pre>
|
||||
|
||||
<p><strong>Example 2:</strong></p>
|
||||
<img alt="" src="https://assets.leetcode.com/uploads/2022/03/15/example2drawio.png" style="width: 165px; height: 165px;" />
|
||||
<pre>
|
||||
<strong>Input:</strong> grid = [[")",")"],["(","("]]
|
||||
<strong>Output:</strong> false
|
||||
<strong>Explanation:</strong> The two possible paths form the parentheses strings "))(" and ")((". Since neither of them are valid parentheses strings, we return false.
|
||||
</pre>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Constraints:</strong></p>
|
||||
|
||||
<ul>
|
||||
<li><code>m == grid.length</code></li>
|
||||
<li><code>n == grid[i].length</code></li>
|
||||
<li><code>1 <= m, n <= 100</code></li>
|
||||
<li><code>grid[i][j]</code> is either <code>'('</code> or <code>')'</code>.</li>
|
||||
</ul>
|
||||
@ -0,0 +1,38 @@
|
||||
<p>Given the <code>root</code> of a binary tree, return <em>the number of nodes where the value of the node is equal to the <strong>average</strong> of the values in its <strong>subtree</strong></em>.</p>
|
||||
|
||||
<p><strong>Note:</strong></p>
|
||||
|
||||
<ul>
|
||||
<li>The <strong>average</strong> of <code>n</code> elements is the <strong>sum</strong> of the <code>n</code> elements divided by <code>n</code> and <strong>rounded down</strong> to the nearest integer.</li>
|
||||
<li>A <strong>subtree</strong> of <code>root</code> is a tree consisting of <code>root</code> and all of its descendants.</li>
|
||||
</ul>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Example 1:</strong></p>
|
||||
<img src="https://assets.leetcode.com/uploads/2022/03/15/image-20220315203925-1.png" style="width: 300px; height: 212px;" />
|
||||
<pre>
|
||||
<strong>Input:</strong> root = [4,8,5,0,1,null,6]
|
||||
<strong>Output:</strong> 5
|
||||
<strong>Explanation:</strong>
|
||||
For the node with value 4: The average of its subtree is (4 + 8 + 5 + 0 + 1 + 6) / 6 = 24 / 6 = 4.
|
||||
For the node with value 5: The average of its subtree is (5 + 6) / 2 = 11 / 2 = 5.
|
||||
For the node with value 0: The average of its subtree is 0 / 1 = 0.
|
||||
For the node with value 1: The average of its subtree is 1 / 1 = 1.
|
||||
For the node with value 6: The average of its subtree is 6 / 1 = 6.
|
||||
</pre>
|
||||
|
||||
<p><strong>Example 2:</strong></p>
|
||||
<img src="https://assets.leetcode.com/uploads/2022/03/26/image-20220326133920-1.png" style="width: 80px; height: 76px;" />
|
||||
<pre>
|
||||
<strong>Input:</strong> root = [1]
|
||||
<strong>Output:</strong> 1
|
||||
<strong>Explanation:</strong> For the node with value 1: The average of its subtree is 1 / 1 = 1.
|
||||
</pre>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Constraints:</strong></p>
|
||||
|
||||
<ul>
|
||||
<li>The number of nodes in the tree is in the range <code>[1, 1000]</code>.</li>
|
||||
<li><code>0 <= Node.val <= 1000</code></li>
|
||||
</ul>
|
||||
48
leetcode/problem/count-number-of-texts.html
Normal file
48
leetcode/problem/count-number-of-texts.html
Normal file
@ -0,0 +1,48 @@
|
||||
<p>Alice is texting Bob using her phone. The <strong>mapping</strong> of digits to letters is shown in the figure below.</p>
|
||||
<img alt="" src="https://assets.leetcode.com/uploads/2022/03/15/1200px-telephone-keypad2svg.png" style="width: 200px; height: 162px;" />
|
||||
<p>In order to <strong>add</strong> a letter, Alice has to <strong>press</strong> the key of the corresponding digit <code>i</code> times, where <code>i</code> is the position of the letter in the key.</p>
|
||||
|
||||
<ul>
|
||||
<li>For example, to add the letter <code>'s'</code>, Alice has to press <code>'7'</code> four times. Similarly, to add the letter <code>'k'</code>, Alice has to press <code>'5'</code> twice.</li>
|
||||
<li>Note that the digits <code>'0'</code> and <code>'1'</code> do not map to any letters, so Alice <strong>does not</strong> use them.</li>
|
||||
</ul>
|
||||
|
||||
<p>However, due to an error in transmission, Bob did not receive Alice's text message but received a <strong>string of pressed keys</strong> instead.</p>
|
||||
|
||||
<ul>
|
||||
<li>For example, when Alice sent the message <code>"bob"</code>, Bob received the string <code>"2266622"</code>.</li>
|
||||
</ul>
|
||||
|
||||
<p>Given a string <code>pressedKeys</code> representing the string received by Bob, return <em>the <strong>total number of possible text messages</strong> Alice could have sent</em>.</p>
|
||||
|
||||
<p>Since the answer may be very large, return it <strong>modulo</strong> <code>10<sup>9</sup> + 7</code>.</p>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Example 1:</strong></p>
|
||||
|
||||
<pre>
|
||||
<strong>Input:</strong> pressedKeys = "22233"
|
||||
<strong>Output:</strong> 8
|
||||
<strong>Explanation:</strong>
|
||||
The possible text messages Alice could have sent are:
|
||||
"aaadd", "abdd", "badd", "cdd", "aaae", "abe", "bae", and "ce".
|
||||
Since there are 8 possible messages, we return 8.
|
||||
</pre>
|
||||
|
||||
<p><strong>Example 2:</strong></p>
|
||||
|
||||
<pre>
|
||||
<strong>Input:</strong> pressedKeys = "222222222222222222222222222222222222"
|
||||
<strong>Output:</strong> 82876089
|
||||
<strong>Explanation:</strong>
|
||||
There are 2082876103 possible text messages Alice could have sent.
|
||||
Since we need to return the answer modulo 10<sup>9</sup> + 7, we return 2082876103 % (10<sup>9</sup> + 7) = 82876089.
|
||||
</pre>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Constraints:</strong></p>
|
||||
|
||||
<ul>
|
||||
<li><code>1 <= pressedKeys.length <= 10<sup>5</sup></code></li>
|
||||
<li><code>pressedKeys</code> only consists of digits from <code>'2'</code> - <code>'9'</code>.</li>
|
||||
</ul>
|
||||
49
leetcode/problem/largest-3-same-digit-number-in-string.html
Normal file
49
leetcode/problem/largest-3-same-digit-number-in-string.html
Normal file
@ -0,0 +1,49 @@
|
||||
<p>You are given a string <code>num</code> representing a large integer. An integer is <strong>good</strong> if it meets the following conditions:</p>
|
||||
|
||||
<ul>
|
||||
<li>It is a <strong>substring</strong> of <code>num</code> with length <code>3</code>.</li>
|
||||
<li>It consists of only one unique digit.</li>
|
||||
</ul>
|
||||
|
||||
<p>Return <em>the <strong>maximum good </strong>integer as a <strong>string</strong> or an empty string </em><code>""</code><em> if no such integer exists</em>.</p>
|
||||
|
||||
<p>Note:</p>
|
||||
|
||||
<ul>
|
||||
<li>A <strong>substring</strong> is a contiguous sequence of characters within a string.</li>
|
||||
<li>There may be <strong>leading zeroes</strong> in <code>num</code> or a good integer.</li>
|
||||
</ul>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Example 1:</strong></p>
|
||||
|
||||
<pre>
|
||||
<strong>Input:</strong> num = "6<strong><u>777</u></strong>133339"
|
||||
<strong>Output:</strong> "777"
|
||||
<strong>Explanation:</strong> There are two distinct good integers: "777" and "333".
|
||||
"777" is the largest, so we return "777".
|
||||
</pre>
|
||||
|
||||
<p><strong>Example 2:</strong></p>
|
||||
|
||||
<pre>
|
||||
<strong>Input:</strong> num = "23<strong><u>000</u></strong>19"
|
||||
<strong>Output:</strong> "000"
|
||||
<strong>Explanation:</strong> "000" is the only good integer.
|
||||
</pre>
|
||||
|
||||
<p><strong>Example 3:</strong></p>
|
||||
|
||||
<pre>
|
||||
<strong>Input:</strong> num = "42352338"
|
||||
<strong>Output:</strong> ""
|
||||
<strong>Explanation:</strong> No substring of length 3 consists of only one unique digit. Therefore, there are no good integers.
|
||||
</pre>
|
||||
|
||||
<p> </p>
|
||||
<p><strong>Constraints:</strong></p>
|
||||
|
||||
<ul>
|
||||
<li><code>3 <= num.length <= 1000</code></li>
|
||||
<li><code>num</code> only consists of digits.</li>
|
||||
</ul>
|
||||
Loading…
Reference in New Issue
Block a user