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            "title": "Longest String Chain",
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            "content": "<p>You are given an array of <code>words</code> where each word consists of lowercase English letters.</p>\n\n<p><code>word<sub>A</sub></code> is a <strong>predecessor</strong> of <code>word<sub>B</sub></code> if and only if we can insert <strong>exactly one</strong> letter anywhere in <code>word<sub>A</sub></code> <strong>without changing the order of the other characters</strong> to make it equal to <code>word<sub>B</sub></code>.</p>\n\n<ul>\n\t<li>For example, <code>&quot;abc&quot;</code> is a <strong>predecessor</strong> of <code>&quot;ab<u>a</u>c&quot;</code>, while <code>&quot;cba&quot;</code> is not a <strong>predecessor</strong> of <code>&quot;bcad&quot;</code>.</li>\n</ul>\n\n<p>A <strong>word chain</strong><em> </em>is a sequence of words <code>[word<sub>1</sub>, word<sub>2</sub>, ..., word<sub>k</sub>]</code> with <code>k &gt;= 1</code>, where <code>word<sub>1</sub></code> is a <strong>predecessor</strong> of <code>word<sub>2</sub></code>, <code>word<sub>2</sub></code> is a <strong>predecessor</strong> of <code>word<sub>3</sub></code>, and so on. A single word is trivially a <strong>word chain</strong> with <code>k == 1</code>.</p>\n\n<p>Return <em>the <strong>length</strong> of the <strong>longest possible word chain</strong> with words chosen from the given list of </em><code>words</code>.</p>\n\n<p>&nbsp;</p>\n<p><strong>Example 1:</strong></p>\n\n<pre>\n<strong>Input:</strong> words = [&quot;a&quot;,&quot;b&quot;,&quot;ba&quot;,&quot;bca&quot;,&quot;bda&quot;,&quot;bdca&quot;]\n<strong>Output:</strong> 4\n<strong>Explanation</strong>: One of the longest word chains is [&quot;a&quot;,&quot;<u>b</u>a&quot;,&quot;b<u>d</u>a&quot;,&quot;bd<u>c</u>a&quot;].\n</pre>\n\n<p><strong>Example 2:</strong></p>\n\n<pre>\n<strong>Input:</strong> words = [&quot;xbc&quot;,&quot;pcxbcf&quot;,&quot;xb&quot;,&quot;cxbc&quot;,&quot;pcxbc&quot;]\n<strong>Output:</strong> 5\n<strong>Explanation:</strong> All the words can be put in a word chain [&quot;xb&quot;, &quot;xb<u>c</u>&quot;, &quot;<u>c</u>xbc&quot;, &quot;<u>p</u>cxbc&quot;, &quot;pcxbc<u>f</u>&quot;].\n</pre>\n\n<p><strong>Example 3:</strong></p>\n\n<pre>\n<strong>Input:</strong> words = [&quot;abcd&quot;,&quot;dbqca&quot;]\n<strong>Output:</strong> 1\n<strong>Explanation:</strong> The trivial word chain [&quot;abcd&quot;] is one of the longest word chains.\n[&quot;abcd&quot;,&quot;dbqca&quot;] is not a valid word chain because the ordering of the letters is changed.\n</pre>\n\n<p>&nbsp;</p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>1 &lt;= words.length &lt;= 1000</code></li>\n\t<li><code>1 &lt;= words[i].length &lt;= 16</code></li>\n\t<li><code>words[i]</code> only consists of lowercase English letters.</li>\n</ul>\n",
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                    "code": "class Solution {\npublic:\n    int longestStrChain(vector<string>& words) {\n        \n    }\n};",
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                    "code": "class Solution(object):\n    def longestStrChain(self, words):\n        \"\"\"\n        :type words: List[str]\n        :rtype: int\n        \"\"\"\n        ",
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                    "code": "/**\n * @param {string[]} words\n * @return {number}\n */\nvar longestStrChain = function(words) {\n    \n};",
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                    "code": "# @param {String[]} words\n# @return {Integer}\ndef longest_str_chain(words)\n    \nend",
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                    "code": "impl Solution {\n    pub fn longest_str_chain(words: Vec<String>) -> i32 {\n        \n    }\n}",
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                    "code": "-spec longest_str_chain(Words :: [unicode:unicode_binary()]) -> integer().\nlongest_str_chain(Words) ->\n  .",
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                    "code": "defmodule Solution do\n  @spec longest_str_chain(words :: [String.t]) :: integer\n  def longest_str_chain(words) do\n\n  end\nend",
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            "hints": [
                "Instead of adding a character, try deleting a character to form a chain in reverse.",
                "For each word in order of length, for each word2 which is word with one character removed, length[word2] = max(length[word2], length[word] + 1)."
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