CUBE-122: COI Board Game !

#include<stdio.h>
#include<queue>
using namespace std;
int n,m;

struct pos{
    int I,J;
    pos operator + (const pos& rhs)const
    {
        return {I + rhs.I , J + rhs.J};
    }
};

bool isinbound(pos p){
    return ( (0 <= p.I && p.I < n ) && (0 <= p.J && p.J < m) );
}

struct elem{
    int key;
    pos now;
};

int min(int a,int b)
{
    return (a < b ? a : b);
}
int main()
{

    scanf("%d %d",&n,&m);
    char board[n][m+1];
    for(int i = 0 ; i < n ; i ++){
        scanf(" %s",board[i]);
    }
    pos begin , end;
    for(int i = 0 ; i< n ; i ++){
        for(int j = 0 ; j < m ; j ++){
            if(board[i][j] == 'S'){
                begin.I = i;
                begin.J = j;
            }
            if(board[i][j] == 'E'){
                end.I = i;
                end.J = j;
            }
        }
    }

    bool visited[8][n][m]; // J = 1(1<<0) , B = 2(1<<1) , P = 4(1<<2) , JB = 3 , JP = 5 , BP = 6 , JBP = 7
    int dist[8][n][m];
    for(int key = 0 ; key < 8 ; key ++){ //
        for(int i = 0 ; i < n ; i ++){
            for(int j = 0 ; j < m ; j ++){
                visited[key][i][j] = false;
                dist[key][i][j] = 1e9;
            }
        }
    }
    dist[0][begin.I][begin.J] = 0;
    queue<elem> q;
    q.push({0,{begin.I , begin.J} });

    while(!q.empty()){
        int key = q.front().key;
        pos now = q.front().now;
        q.pop();
    /*  if(visited[key][now.I][now.J])continue;
        visited[key][now.I][now.J] = true;*/

    //  printf("Test at (%d,%d) with #%d key \n",now.I,now.J,key);
        pos move[4] = { {-1,0} , {0,1} , {1,0} , {0,-1} };
        for(int i = 0 ; i < 4 ; i ++){
            pos nxt = now + move[i];
            if(isinbound(nxt))
            {
            //  if(visited[key][nxt.I][nxt.J])continue;

                char nxtonB = board[nxt.I][nxt.J];
                if(nxtonB == '#'){
                    continue;
                }
                else if(nxtonB == '.' || nxtonB == 'S'){
                    if(dist[key][nxt.I][nxt.J] > dist[key][now.I][now.J] + 1){
                        dist[key][nxt.I][nxt.J] = dist[key][now.I][now.J] + 1;
                        q.push({key,nxt});
                    }
            //      printf("go to (%d,%d)\n",nxt.I,nxt.J);
                }
                else if(nxtonB == 'j'){ // get j key
                    if(dist[key|(1<<0)][nxt.I][nxt.J] > dist[key][now.I][now.J] + 1){
                        dist[key|(1<<0)][nxt.I][nxt.J] = dist[key][now.I][now.J] + 1;
                        q.push({key|(1<<0),nxt});
                    }
            //      printf("go to (%d,%d)\n",nxt.I,nxt.J);
                }
                else if(nxtonB == 'b'){ // get b key
                    if(dist[key|(1<<1)][nxt.I][nxt.J] > dist[key][now.I][now.J] + 1){
                        dist[key|(1<<1)][nxt.I][nxt.J] = dist[key][now.I][now.J] + 1;
                        q.push({key|(1<<1),nxt});
                    }
            //      printf("go to (%d,%d)\n",nxt.I,nxt.J);
                }
                else if(nxtonB == 'p'){ // get p key
                    if(dist[key|(1<<2)][nxt.I][nxt.J] > dist[key][now.I][now.J] + 1){
                        dist[key|(1<<2)][nxt.I][nxt.J] = dist[key][now.I][now.J] + 1;
                        q.push({key|(1<<2),nxt});
                    }
            //      printf("go to (%d,%d)\n",nxt.I,nxt.J);
                }
                else if(nxtonB == 'J' && (key&(1<<0))){ //have J key
                    if(dist[key][nxt.I][nxt.J] > dist[key][now.I][now.J] + 1){
                        dist[key][nxt.I][nxt.J] = dist[key][now.I][now.J] + 1;
                        q.push({key,nxt});
                    }
            //      printf("go to (%d,%d)\n",nxt.I,nxt.J);
                }
                else if(nxtonB == 'B' && (key&(1<<1))){ //have B key
                    if(dist[key][nxt.I][nxt.J] > dist[key][now.I][now.J] + 1){
                        dist[key][nxt.I][nxt.J] = dist[key][now.I][now.J] + 1;
                        q.push({key,nxt});
                    }
            //      printf("go to (%d,%d)\n",nxt.I,nxt.J);
                }
                else if(nxtonB == 'P' && (key&(1<<2))){ //have P key
                    if(dist[key][nxt.I][nxt.J] > dist[key][now.I][now.J] + 1){
                        dist[key][nxt.I][nxt.J] = dist[key][now.I][now.J] + 1;
                        q.push({key,nxt});
                    }
            //      printf("go to (%d,%d)\n",nxt.I,nxt.J);
                }
                else if(nxtonB == 'E'){
                    if(dist[key][nxt.I][nxt.J] > dist[key][now.I][now.J] + 1){
                        dist[key][nxt.I][nxt.J] = dist[key][now.I][now.J] + 1;
                    }
            //      printf("Test goal cost : %d\n",dist[key][nxt.I][nxt.J]);
                    break;
                }
            }
        }
    }
    int ans = 1e9;
    for(int i = 0 ; i < 8 ; i ++){
    //  printf("checking #%d with %d < %d ? \n",i,dist[i][end.I][end.J],ans);
        ans = min(ans,dist[i][end.I][end.J]);
    }
    printf("%d",(ans == 1e9 ? -1 : ans));
    return 0;
}