"content":"<p>Bob is standing at cell <code>(0, 0)</code>, and he wants to reach <code>destination</code>: <code>(row, column)</code>. He can only travel <strong>right</strong> and <strong>down</strong>. You are going to help Bob by providing <strong>instructions</strong> for him to reach <code>destination</code>.</p>\n\n<p>The <strong>instructions</strong> are represented as a string, where each character is either:</p>\n\n<ul>\n\t<li><code>'H'</code>, meaning move horizontally (go <strong>right</strong>), or</li>\n\t<li><code>'V'</code>, meaning move vertically (go <strong>down</strong>).</li>\n</ul>\n\n<p>Multiple <strong>instructions</strong> will lead Bob to <code>destination</code>. For example, if <code>destination</code> is <code>(2, 3)</code>, both <code>"HHHVV"</code> and <code>"HVHVH"</code> are valid <strong>instructions</strong>.</p>\n\n<p>However, Bob is very picky. Bob has a lucky number <code>k</code>, and he wants the <code>k<sup>th</sup></code> <strong>lexicographically smallest instructions</strong> that will lead him to <code>destination</code>. <code>k</code> is <strong>1-indexed</strong>.</p>\n\n<p>Given an integer array <code>destination</code> and an integer <code>k</code>, return <em>the </em><code>k<sup>th</sup></code><em> <strong>lexicographically smallest instructions</strong> that will take Bob to </em><code>destination</code>.</p>\n\n<p> </p>\n<p><strong class=\"example\">Example 1:</strong></p>\n\n<p><img alt=\"\" src=\"https://assets.leetcode.com/uploads/2020/10/12/ex1.png\" style=\"width: 300px; height: 229px;\" /></p>\n\n<pre>\n<strong>Input:</strong> destination = [2,3], k = 1\n<strong>Output:</strong> "HHHVV"\n<strong>Explanation:</strong> All the instructions that reach (2, 3) in lexicographic order are as follows:\n["HHHVV", "HHVHV", "HHVVH", "HVHHV", "HVHVH", "HVVHH", "VHHHV", "VHHVH", "VHVHH", "VVHHH"].\n</pre>\n\n<p><strong class=\"example\">Example 2:</strong></p>\n\n<p><strong><img alt=\"\" src=\"https://assets.leetcode.com/uploads/2020/10/12/ex2.png\" style=\"width: 300px; height: 229px;\" /></strong></p>\n\n<pre>\n<strong>Input:</strong> destination = [2,3], k = 2\n<strong>Output:</strong> "HHVHV"\n</pre>\n\n<p><strong class=\"example\">Example 3:</strong></p>\n\n<p><strong><img alt=\"\" src=\"https://assets.leetcode.com/uploads/2020/10/12/ex3.png\" style=\"width: 300px; height: 229px;\" /></strong></p>\n\n<pre>\n<strong>Input:</strong> destination = [2,3], k = 3\n<strong>Output:</strong> "HHVVH"\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>destination.length == 2</code></li>\n\t<li><code>1 <= row, column <= 15</code></li>\n\t<li><code>1 <= k <= nCr(row + column, row)</code>, where <code>nCr(a, b)</code> denotes <code>a</code> choose <code>b</code>.</li>\n</ul>\n",
"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