AcWing 845. eight digital

https://www.acwing.com/problem/content/847/

#include <bits / STDC ++ H.>
 the using  namespace STD;
 int BFS ( String Start) 
{ 
    String End = " 12345678x " ; 
    Queue < String > Q;   
    unordered_map < String , int > D;   // distance array 
    q.push (start );   // put into the start to 
    D [start] = 0 ;   // start point to the starting point distance of 0 
    int DX [ . 4 ] = { 0 , 0 , . 1 , - . 1}, Dy [ . 4 ] = { . 1 , - . 1 , 0 , 0 };
     the while (q.size ()) 
    { 
        Auto T = q.front ();    
        q.pop (); 
        int Distance = D [T];
         IF (t == end) return Distance;   // determines whether t is terminated if the end 
         // state transition 
        int K = t.find ( ' x ' );    // first find the position x of the subscript x return 
        int K = X / . 3 , Y =% K . 3 ;     // the one dimension array to convert a two-dimensional 3x3 matrix array subscript
        for ( int I = 0 ; I < . 4 ; I ++ ) 
        { 
            int A = X + DX [I], B = Y + Dy [I]; // coordinate after the change 
            IF (A> = 0 && A < . 3 && B> = 0 && B < . 3 )    // If not out of bounds 
            { 
                the swap (T [K], T [A * . 3 + B]);   // after update exchange must be completed recovery state update 
                IF (d.count (T!) )    // If t is after the current has not been found to have updated it had found a new state 
                { 
                    D [t] = Distance + . 1 ;      //Plus the distance. 1 
                    q.push (T);   // pressed into queue 
                } 
                the swap (T [K], T [A * . 3 + B]);   // recovery state 
            } 
    
            
         } 
    } 
    return - . 1 ; 
} 
int main () {
     string Start;   // initially given string 
    for ( int I = 0 ; I < . 9 ; I ++ ) {
         char C; 
        CIN >> C; 
        Start + = C; 
    } 
    COUT<<bfs(start)<<endl;
}