<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 {
    bool isvalid( int row, int col,vector<vector<int>>& grid){
        if(row<0||row>=grid.size()) return false;
        if(col<0||col>=grid[0].size()) return false;
        return true;
    }
   int dr[4]={-1,0,1,0};
    int dc[4]={0,1,0,-1};
public:
    vector<vector<int>> res={{1,2,3},{4,5,0}};
    int bfs(int x,int y,vector<vector<int>>&board){
        queue<pair<vector<vector<int>>,pair<int,int>>> q;
        map<vector<vector<int>>,bool> vis;
        vis[board]=true;
        q.push({board,{x,y}});
        for(int level=0,sz=1 ;!q.empty();sz=q.size(),level++){
          
            while(sz--){
               
                auto cur=q.front();
                vector<vector<int>> tmp=cur.first;
                int posx=cur.second.first;
                int posy=cur.second.second;
                if(tmp==res) return level;
               
                q.pop();
                for(int i=0;i<4;i++){ 
                    if(isvalid(posx+dr[i],posy+dc[i],board)){
                        swap(tmp[posx][posy],tmp[posx+dr[i]][posy+dc[i]]);
                        if(!vis[tmp]){
                        q.push({tmp,{posx+dr[i],posy+dc[i]}});
                        vis[tmp]=true;
                        }
                        tmp=cur.first;
                    }
                }
            }
        }
        return -1;
    }
    int slidingPuzzle(vector<vector<int>>& board) {
        int x,y;
        for(int i=0;i<2;i++){
            for(int j=0;j<3;j++)
            if(board[i][j]==0)
            x=i,y=j;
        }
            if (board==res) return 0;
        return bfs(x,y,board);
    }

};
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