"content":"<p>A storekeeper is a game in which the player pushes boxes around in a warehouse trying to get them to target locations.</p>\n\n<p>The game is represented by an <code>m x n</code> grid of characters <code>grid</code> where each element is a wall, floor, or box.</p>\n\n<p>Your task is to move the box <code>'B'</code> to the target position <code>'T'</code> under the following rules:</p>\n\n<ul>\n\t<li>The character <code>'S'</code> represents the player. The player can move up, down, left, right in <code>grid</code> if it is a floor (empty cell).</li>\n\t<li>The character <code>'.'</code> represents the floor which means a free cell to walk.</li>\n\t<li>The character <code>'#' </code>represents the wall which means an obstacle (impossible to walk there).</li>\n\t<li>There is only one box <code>'B'</code> and one target cell <code>'T'</code> in the <code>grid</code>.</li>\n\t<li>The box can be moved to an adjacent free cell by standing next to the box and then moving in the direction of the box. This is a <strong>push</strong>.</li>\n\t<li>The player cannot walk through the box.</li>\n</ul>\n\n<p>Return <em>the minimum number of <strong>pushes</strong> to move the box to the target</em>. If there is no way to reach the target, return <code>-1</code>.</p>\n\n<p> </p>\n<p><strong>Example 1:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2019/11/06/sample_1_1620.png\" style=\"width: 500px; height: 335px;\"/>\n<pre>\n<strong>Input:</strong>grid=[["#","#","#","#","#","#"],\n["#","T","#","#","#","#"],\n["#",".",".","B",".","#"],\n["#",".","#","#",".","#"],\n["#",".",".",".","S","#"],\n["#","#","#","#","#","#"]]\n<strong>Output:</strong>3\n<strong>Explanation:</strong>Wereturnonlythenumberoftimestheboxispushed.</pre>\n\n<p><strong>Example2:</strong></p>\n\n<pre>\n<strong>Input:</strong>grid=[["#","#","#","#","#","#"],\n["#","T","#","#","#","#"],\n["#",".",".","B",".","#"],\n["#","#","#","#",".","#"],\n["#",".",".",".","S","#"],\n["#","#","#","#","#","#"]]\n<strong>Output:</strong>-1\n</pre>\n\n<p><strong>Example3:</strong></p>\n\n<pre>\n<strong>Input:</strong>grid=[["#","#","#","#","#","#"],\n["#","T",".",".","#","#"],\n["#",".","#","B",".","#"],\n["#",".",".",".",".","#"],\n["#",".",".",".","S","#"],\n["#","#","#","#","#","#"]]\n<strong>Output:</strong>5\n<strong>Explanation:</strong>pushtheboxdown,left,left,upandup.\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>m==grid.length</code></li>\n\t<li><code>n==grid[i].length</code></li>\n\t<li><code>1<=m,n<=20</code></li>\n\t<li><code>grid</code>containsonlycharacters<code>'.'</code>,<code>'#&#
"We represent the search state as (player_row, player_col, box_row, box_col).",
"You need to count only the number of pushes. Then inside of your BFS check if the box could be pushed (in any direction) given the current position of the player."
"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:
