<p>On an <code>2 x 3</code> board, there are five tiles labeled from <code>1</code> to <code>5</code>, and an empty square represented by <code>0</code>. A <strong>move</strong> consists of choosing <code>0</code> and a 4-directionally adjacent number and swapping it.</p>

<p>The state of the board is solved if and only if the board is <code>[[1,2,3],[4,5,0]]</code>.</p>

<p>Given the puzzle board <code>board</code>, return <em>the least number of moves required so that the state of the board is solved</em>. If it is impossible for the state of the board to be solved, return <code>-1</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/06/29/slide1-grid.jpg" style="width: 244px; height: 165px;" />
<pre>
<strong>Input:</strong> board = [[1,2,3],[4,0,5]]
<strong>Output:</strong> 1
<strong>Explanation:</strong> Swap the 0 and the 5 in one move.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/06/29/slide2-grid.jpg" style="width: 244px; height: 165px;" />
<pre>
<strong>Input:</strong> board = [[1,2,3],[5,4,0]]
<strong>Output:</strong> -1
<strong>Explanation:</strong> No number of moves will make the board solved.
</pre>

<p><strong class="example">Example 3:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/06/29/slide3-grid.jpg" style="width: 244px; height: 165px;" />
<pre>
<strong>Input:</strong> board = [[4,1,2],[5,0,3]]
<strong>Output:</strong> 5
<strong>Explanation:</strong> 5 is the smallest number of moves that solves the board.
An example path:
After move 0: [[4,1,2],[5,0,3]]
After move 1: [[4,1,2],[0,5,3]]
After move 2: [[0,1,2],[4,5,3]]
After move 3: [[1,0,2],[4,5,3]]
After move 4: [[1,2,0],[4,5,3]]
After move 5: [[1,2,3],[4,5,0]]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>board.length == 2</code></li>
	<li><code>board[i].length == 3</code></li>
	<li><code>0 &lt;= board[i][j] &lt;= 5</code></li>
	<li>Each value <code>board[i][j]</code> is <strong>unique</strong>.</li>
</ul>

class Solution {
public:
int slidingPuzzle(vector<vector<int>>& brd) 
{
    queue<vector<vector<int>>> q;
    int i=0,iz,jz,m,n,c;
    vector<vector<int>> f,dum,req=brd;
    map<vector<vector<int>>,int> vst,dst;
    vst[brd]=1;
    q.push(brd);
    while (!q.empty())
    {
        f=q.front(),m=0,n=0;
        while (m<2)
        {
            n=0;
            while (n<3)
            {
                if (f[m][n]==0)
                {
                    iz=m,jz=n;
                    break;
                }
                n++;
            }
            m++;
        }
        dum=f;
        if (iz==0)
        {
            dum[iz][jz]=dum[iz+1][jz];
            dum[iz+1][jz]=0;
            if (vst[dum]==0)
            {
                vst[dum]=1;
                q.push(dum);
                dst[dum]=dst[f]+1;
            }
        }
        if (iz==1)
        {
            dum[iz][jz]=dum[iz-1][jz];
            dum[iz-1][jz]=0;
            if (vst[dum]==0)
            {
                vst[dum]=1;
                q.push(dum);
                dst[dum]=dst[f]+1;
            }
        }
        dum=f;
        if (jz+1<3)
        {
            dum[iz][jz]=dum[iz][jz+1];
            dum[iz][jz+1]=0;
            if (vst[dum]==0)
            {
                vst[dum]=1;
                q.push(dum);
                dst[dum]=dst[f]+1;
            }
        }
        dum=f;
        if (jz-1>=0)
        {
            dum[iz][jz]=dum[iz][jz-1];
            dum[iz][jz-1]=0;
            if (vst[dum]==0)
            {
                vst[dum]=1;
                q.push(dum);
                dst[dum]=dst[f]+1;
            }
        }
        q.pop(); 
    }
    req[0][0]=1,req[0][1]=2,req[0][2]=3,req[1][0]=4,req[1][1]=5,req[1][2]=0;
    if (vst[req])
    {
        return dst[req];
    }
    return -1;
}
};
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