"content":"<p>A <strong>wonderful</strong> string is a string where <strong>at most one</strong> letter appears an <strong>odd</strong> number of times.</p>\r\n\r\n<ul>\r\n\t<li>For example, <code>"ccjjc"</code> and <code>"abab"</code> are wonderful, but <code>"ab"</code> is not.</li>\r\n</ul>\r\n\r\n<p>Given a string <code>word</code> that consists of the first ten lowercase English letters (<code>'a'</code> through <code>'j'</code>), return <em>the <strong>number of wonderful non-empty substrings</strong> in </em><code>word</code><em>. If the same substring appears multiple times in </em><code>word</code><em>, then count <strong>each occurrence</strong> separately.</em></p>\r\n\r\n<p>A <strong>substring</strong> is a contiguous sequence of characters in a string.</p>\r\n\r\n<p> </p>\r\n<p><strong class=\"example\">Example 1:</strong></p>\r\n\r\n<pre>\r\n<strong>Input:</strong> word = "aba"\r\n<strong>Output:</strong> 4\r\n<strong>Explanation:</strong> The four wonderful substrings are underlined below:\r\n- "<u><strong>a</strong></u>ba" -> "a"\r\n- "a<u><strong>b</strong></u>a" -> "b"\r\n- "ab<u><strong>a</strong></u>" -> "a"\r\n- "<u><strong>aba</strong></u>" -> "aba"\r\n</pre>\r\n\r\n<p><strong class=\"example\">Example 2:</strong></p>\r\n\r\n<pre>\r\n<strong>Input:</strong> word = "aabb"\r\n<strong>Output:</strong> 9\r\n<strong>Explanation:</strong> The nine wonderful substrings are underlined below:\r\n- "<strong><u>a</u></strong>abb" -> "a"\r\n- "<u><strong>aa</strong></u>bb" -> "aa"\r\n- "<u><strong>aab</strong></u>b" -> "aab"\r\n- "<u><strong>aabb</strong></u>" -> "aabb"\r\n- "a<u><strong>a</strong></u>bb" -> "a"\r\n- "a<u><strong>abb</strong></u>" -> "abb"\r\n- "aa<u><strong>b</strong></u>b" -> "b"\r\n- "aa<u><strong>bb</strong></u>" -> "bb"\r\n- "aab<u><strong>b</strong></u>" -> "b"\r\n</pre>\r\n\r\n<p><strong class=\"example\">Example 3:</strong></p>\r\n\r\n<pre>\r\n<strong>Input:</strong> word = "he"\r\n<strong>Output:</strong> 2\r\n<strong>Explanation:</strong> The two wonderful substrings are underlined below:\r\n- "<b><u>h</u></b>e" -> "h"\r\n- "h<strong><u>e</u></strong>" -> "e"\r\n</pre>\r\n\r\n<p> </p>\r\n<p><strong>Constraints:</strong></p>\r\n\r\n<ul>\r\n\t<li><code>1 <= word.length <= 10<sup>5</sup></code></li>\r\n\t<li><code>word</code> consists of lowercase English letters from <code>'a'</code> to <code>'j'</code>.</li>\r\n</ul>",
"envInfo":"{\"cpp\": [\"C++\", \"<p>Compiled with <code> clang 11 </code> using the latest C++ 20 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 gnu11 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://learn.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-10\\\" target=\\\"_blank\\\">C# 10 with .NET 6 runtime</a></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 5.3.0 version of <a href=\\\"https://github.com/datastructures-js/priority-queue/tree/fb4fdb984834421279aeb081df7af624d17c2a03\\\" target=\\\"_blank\\\">datastructures-js/priority-queue</a> and 4.2.1 version of <a href=\\\"https://githu
