HDOJ 1180

我的code: 超时，不知道怎么优化，望大神指点

#include<iostream>
#include <string>
#include <queue>
using namespace std;

struct StepPoint  
{
    int X,Y,Val;
    const bool operator<(const StepPoint &x)const { return x.Val<Val; }
};
StepPoint beginP,endP;
static int moves[4][2]={-1,0,0,-1,1,0,0,1};
char maps[22][22];

int StepBFS()
{
    priority_queue<StepPoint> q;
    q.push(beginP);
    while (!q.empty())
    {
        StepPoint p=q.top();
        q.pop();
        StepPoint p1=p;
        p1.Val++;
        q.push(p1);

        for (int i=0;i<4;i++)
        {
            int x=p.X+moves[i][0];
            int y=p.Y+moves[i][1];
            if(maps[x][y]=='.')
            {
                StepPoint pNew;
                pNew.X=x;pNew.Y=y;pNew.Val=p.Val+1;
                q.push(pNew);
                maps[x][y]=='*';
            }
            else if(maps[x][y]=='|'&&(
                ( (p.Val+1)%2==0&&(i==0||i==2)) ||
                ( (p.Val+1)%2!=0&&(i==1||i==3)) ))
            {
                StepPoint pNews;
                pNews.X=x+moves[i][0];
                pNews.Y=y+moves[i][1];
                pNews.Val=p.Val+1;
                if(maps[pNews.X][pNews.Y]=='.')
                {
                    q.push(pNews);
                    maps[pNews.X][pNews.Y]=='*';
                }
            }
            else if(maps[x][y]=='-'&&(
                ( (p.Val+1)%2==0&&(i==1||i==3)) ||
                ( (p.Val+1)%2!=0&&(i==0||i==2)) ))
            {
                StepPoint pNews;
                pNews.X=x+moves[i][0];
                pNews.Y=y+moves[i][1];
                pNews.Val=p.Val+1;
                if(maps[pNews.X][pNews.Y]=='.')
                {
                    q.push(pNews);
                    maps[pNews.X][pNews.Y]=='*';
                }
            }
            else if(maps[x][y]=='T')
                return p.Val+1;
        }
    }
}

int main()
{
    int n,m,i,j;
    
    while(cin>>n>>m)
    {
        for (i=0;i<22;i++)
        {
            memset(maps[i],'*',sizeof(maps[i]));
        }
        
        for (i=1;i<=n;i++)
        {
            for (j=1;j<=m;j++)
            {
                cin>>maps[i][j];
                if(maps[i][j]=='S')
                {
                    beginP.X=i;
                    beginP.Y=j;
                    beginP.Val=0;
                }
                if(maps[i][j]=='T')
                {
                    endP.X=i;
                    endP.Y=j;
                }
            }
        }
        cout<<StepBFS()<<endl;
    }
    return 0;
}