"content":"<p>You are given two <strong>0-indexed</strong> arrays of strings <code>startWords</code> and <code>targetWords</code>. Each string consists of <strong>lowercase English letters</strong> only.</p>\n\n<p>For each string in <code>targetWords</code>, check if it is possible to choose a string from <code>startWords</code> and perform a <strong>conversion operation</strong> on it to be equal to that from <code>targetWords</code>.</p>\n\n<p>The <strong>conversion operation</strong> is described in the following two steps:</p>\n\n<ol>\n\t<li><strong>Append</strong> any lowercase letter that is <strong>not present</strong> in the string to its end.\n\n\t<ul>\n\t\t<li>For example, if the string is <code>"abc"</code>, the letters <code>'d'</code>, <code>'e'</code>, or <code>'y'</code> can be added to it, but not <code>'a'</code>. If <code>'d'</code> is added, the resulting string will be <code>"abcd"</code>.</li>\n\t</ul>\n\t</li>\n\t<li><strong>Rearrange</strong> the letters of the new string in <strong>any</strong> arbitrary order.\n\t<ul>\n\t\t<li>For example, <code>"abcd"</code> can be rearranged to <code>"acbd"</code>, <code>"bacd"</code>, <code>"cbda"</code>, and so on. Note that it can also be rearranged to <code>"abcd"</code> itself.</li>\n\t</ul>\n\t</li>\n</ol>\n\n<p>Return <em>the <strong>number of strings</strong> in </em><code>targetWords</code><em> that can be obtained by performing the operations on <strong>any</strong> string of </em><code>startWords</code>.</p>\n\n<p><strong>Note</strong> that you will only be verifying if the string in <code>targetWords</code> can be obtained from a string in <code>startWords</code> by performing the operations. The strings in <code>startWords</code> <strong>do not</strong> actually change during this process.</p>\n\n<p> </p>\n<p><strong>Example 1:</strong></p>\n\n<pre>\n<strong>Input:</strong> startWords = ["ant","act","tack"], targetWords = ["tack","act","acti"]\n<strong>Output:</strong> 2\n<strong>Explanation:</strong>\n- In order to form targetWords[0] = "tack", we use startWords[1] = "act", append 'k' to it, and rearrange "actk" to "tack".\n- There is no string in startWords that can be used to obtain targetWords[1] = "act".\n Note that "act" does exist in startWords, but we <strong>must</strong> append one letter to the string before rearranging it.\n- In order to form targetWords[2] = "acti", we use startWords[1] = "act", append 'i' to it, and rearrange "acti" to "acti" itself.\n</pre>\n\n<p><strong>Example 2:</strong></p>\n\n<pre>\n<strong>Input:</strong> startWords = ["ab","a"], targetWords = ["abc","abcd"]\n<strong>Output:</strong> 1\n<strong>Explanation:</strong>\n- In order to form targetWords[0] = "abc", we use startWords[0] = "ab", add 'c' to it, and rearrange it to "abc".\n- There is no string in startWords that can be used to obtain targetWords[1] = "abcd".\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>1 <= startWords.length, targetWords.length <= 5 * 10<sup>4</sup></code></li>\n\t<li><code>1 <= startWords[i].length, targetWords[j].length <= 26</code></li>\n\t<li>Each string of <code>startWords</code> and <code>targetWords</code> consists of lowercase English letters only.</li>\n\t<li>No letter occurs more than once in any string of <code>startWords</code> or <code>targetWords</code>.</li>\n</ul>\n",
"Which data structure can be used to efficiently check if a string exists in startWords?",
"After appending a letter, all letters of a string can be rearranged in any possible way. How can we use this to reduce our search space while checking if a string in targetWords can be obtained from a string in startWords?"
"envInfo":"{\"cpp\": [\"C++\", \"<p>Compiled with <code> clang 11 </code> using the latest C++ 17 standard.</p>\\r\\n\\r\\n<p>Your code is compiled with level two optimization (<code>-O2</code>). <a href=\\\"https://github.com/google/sanitizers/wiki/AddressSanitizer\\\" target=\\\"_blank\\\">AddressSanitizer</a> is also enabled to help detect out-of-bounds and use-after-free bugs.</p>\\r\\n\\r\\n<p>Most standard library headers are already included automatically for your convenience.</p>\"], \"java\": [\"Java\", \"<p><code> OpenJDK 17 </code>. Java 8 features such as lambda expressions and stream API can be used. </p>\\r\\n\\r\\n<p>Most standard library headers are already included automatically for your convenience.</p>\\r\\n<p>Includes <code>Pair</code> class from https://docs.oracle.com/javase/8/javafx/api/javafx/util/Pair.html.</p>\"], \"python\": [\"Python\", \"<p><code>Python 2.7.12</code>.</p>\\r\\n\\r\\n<p>Most libraries are already imported automatically for your convenience, such as <a href=\\\"https://docs.python.org/2/library/array.html\\\" target=\\\"_blank\\\">array</a>, <a href=\\\"https://docs.python.org/2/library/bisect.html\\\" target=\\\"_blank\\\">bisect</a>, <a href=\\\"https://docs.python.org/2/library/collections.html\\\" target=\\\"_blank\\\">collections</a>. If you need more libraries, you can import it yourself.</p>\\r\\n\\r\\n<p>For Map/TreeMap data structure, you may use <a href=\\\"http://www.grantjenks.com/docs/sortedcontainers/\\\" target=\\\"_blank\\\">sortedcontainers</a> library.</p>\\r\\n\\r\\n<p>Note that Python 2.7 <a href=\\\"https://www.python.org/dev/peps/pep-0373/\\\" target=\\\"_blank\\\">will not be maintained past 2020</a>. For the latest Python, please choose Python3 instead.</p>\"], \"c\": [\"C\", \"<p>Compiled with <code>gcc 8.2</code> using the gnu99 standard.</p>\\r\\n\\r\\n<p>Your code is compiled with level one optimization (<code>-O1</code>). <a href=\\\"https://github.com/google/sanitizers/wiki/AddressSanitizer\\\" target=\\\"_blank\\\">AddressSanitizer</a> is also enabled to help detect out-of-bounds and use-after-free bugs.</p>\\r\\n\\r\\n<p>Most standard library headers are already included automatically for your convenience.</p>\\r\\n\\r\\n<p>For hash table operations, you may use <a href=\\\"https://troydhanson.github.io/uthash/\\\" target=\\\"_blank\\\">uthash</a>. \\\"uthash.h\\\" is included by default. Below are some examples:</p>\\r\\n\\r\\n<p><b>1. Adding an item to a hash.</b>\\r\\n<pre>\\r\\nstruct hash_entry {\\r\\n int id; /* we'll use this field as the key */\\r\\n char name[10];\\r\\n UT_hash_handle hh; /* makes this structure hashable */\\r\\n};\\r\\n\\r\\nstruct hash_entry *users = NULL;\\r\\n\\r\\nvoid add_user(struct hash_entry *s) {\\r\\n HASH_ADD_INT(users, id, s);\\r\\n}\\r\\n</pre>\\r\\n</p>\\r\\n\\r\\n<p><b>2. Looking up an item in a hash:</b>\\r\\n<pre>\\r\\nstruct hash_entry *find_user(int user_id) {\\r\\n struct hash_entry *s;\\r\\n HASH_FIND_INT(users, &user_id, s);\\r\\n return s;\\r\\n}\\r\\n</pre>\\r\\n</p>\\r\\n\\r\\n<p><b>3. Deleting an item in a hash:</b>\\r\\n<pre>\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n HASH_DEL(users, user); \\r\\n}\\r\\n</pre>\\r\\n</p>\"], \"csharp\": [\"C#\", \"<p><a href=\\\"https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-9\\\" target=\\\"_blank\\\">C# 10 with .NET 6 runtime</a></p>\\r\\n\\r\\n<p>Your code is compiled with debug flag enabled (<code>/debug</code>).</p>\"], \"javascript\": [\"JavaScript\", \"<p><code>Node.js 16.13.2</code>.</p>\\r\\n\\r\\n<p>Your code is run with <code>--harmony</code> flag, enabling <a href=\\\"http://node.green/\\\" target=\\\"_blank\\\">new ES6 features</a>.</p>\\r\\n\\r\\n<p><a href=\\\"https://lodash.com\\\" target=\\\"_blank\\\">lodash.js</a> library is included by default.</p>\\r\\n\\r\\n<p>For Priority Queue / Queue data structures, you may use <a href=\\\"https://github.com/datastructures-js/priority-queue\\\" target=\\\"_blank\\\">datastructures-js/priority-queue</a> and <a href=\\\"https:
