<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 x[4]={0,-1,0,1};
int y[4]={-1,0,1,0};
    typedef pair<int ,int> p;
    typedef pair<int ,pair<p ,vector<int>>> pq;
    map<vector<int> ,int> mp;
    int slidingPuzzle(vector<vector<int>>& board) {
        int n=board.size();
        int m=board[0].size();
        int u=-1 ,v;
        vector<int>init;
        for(int i=0;i<n;i++)
        {
            for(int j=0;j<m;j++)
            {
                if(board[i][j] == 0)
                {
                    u=i ,v=j;
                }
                init.push_back(board[i][j]);
            }
        }
        priority_queue<pq ,vector<pq> ,greater<pq>>q;
        vector<int>f={1,2,3,4,5,0};
        q.push({0,{{u,v},init}});
        mp[init]++;
        while(!q.empty()){
            auto it=q.top();
            q.pop();
            auto vec=it.second.second;

            if(vec==f) return it.first;
            int i=it.second.first.first;
            int j=it.second.first.second;
            int swaps=it.first;
    
            cout<<"Hello"<<" ";
            for(int k=0; k<4; k++){
                int ni=i+x[k];
                int nj=j+y[k];
                if(ni>=0 && ni<n && nj>=0 && nj<m){
                    vector<int> arr = vec;
            
                    arr[i*3+j]=arr[ni*3+nj];
                    arr[ni*3+nj]=0;
                    for(auto it : arr) cout<<it<<" ";
                    if(!mp.count(arr)){
                        q.push({swaps+1,{{ni,nj},arr}});
                        mp[arr]++;
                    }
                }
           }
        }
        return -1;
    }
};
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