COI board game

/*
    Task    : _example
    Author  : Phumipat C. [MAGCARI]
    Language: C++
    Created : 06 February 2023 [21:42]
*/
#include<bits/stdc++.h>
using namespace std;
struct A{
    int i,j,mask;
};
queue<A > que;
char a[510][510];
int dis[510][510][10];
int dir[2][4] = {{-1,1,0,0},{0,0,-1,1}};
// J = 0
// B = 1
// P = 2
int main(){
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int n,m,sti,stj;
    cin >> n >> m;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            cin >> a[i][j];
            if(a[i][j] == 'S')
                sti = i,stj = j;
        }
    }

    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            for(int k=0;k<8;k++)
                dis[i][j][k] = 1e9;
    dis[sti][stj][0] = 0;
    que.push({sti,stj,0});
    while(!que.empty()){
        A now = que.front();
        que.pop();
        if(a[now.i][now.j] == 'E'){
            cout << dis[now.i][now.j][now.mask];
            return 0;
        }
        for(int k=0;k<4;k++){
            int ni = now.i+dir[0][k],nj = now.j+dir[1][k];
            if(ni<1 || nj<1 || ni>n || nj>m)    continue;
            if(a[ni][nj] == '#')                continue;
            if(a[ni][nj] == 'J' && (now.mask & (1<<0)) == 0)    continue;
            if(a[ni][nj] == 'B' && (now.mask & (1<<1)) == 0)    continue;
            if(a[ni][nj] == 'P' && (now.mask & (1<<2)) == 0)    continue;
            int nmask = now.mask;
            if(a[ni][nj] == 'j')    nmask |= (1<<0);
            if(a[ni][nj] == 'b')    nmask |= (1<<1);
            if(a[ni][nj] == 'p')    nmask |= (1<<2);

            if(dis[ni][nj][nmask] > dis[now.i][now.j][now.mask]+1){
                dis[ni][nj][nmask] = dis[now.i][now.j][now.mask]+1;
                que.push({ni,nj,nmask});
            }
        }
    }
    cout << "-1\n";
    return 0;
}