hdu 1180 诡异的楼梯 BFS + 优先队列

//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<iostream>
#include<sstream>
#include<cmath>
#include<climits>
#include<string>
#include<map>
#include<queue>
#include<vector>
#include<stack>
#include<set>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
#define pb(a) push(a)
#define INF 0x1f1f1f1f
#define lson idx<<1,l,mid
#define rson idx<<2|1,mid+1,r
#define PI  3.1415926535898
template<class T> T min(const T& a,const T& b,const T& c) {
    return min(min(a,b),min(a,c));
}
template<class T> T max(const T& a,const T& b,const T& c) {
    return max(max(a,b),max(a,c));
}
void debug() {
#ifdef ONLINE_JUDGE
#else

    freopen("d:\in1.txt","r",stdin);
    freopen("d:\out1.txt","w",stdout);
#endif
}
int getch() {
    int ch;
    while((ch=getchar())!=EOF) {
        if(ch!=' '&&ch!='
')return ch;
    }
    return EOF;
}
const int maxn=1000100;
char grid[22][22];
int vis[22][22];
int dx[]={-1,0,1,0};
int dy[]={0,1,0,-1};
int n,m;
struct point
{
    int x,y,t;
    bool operator < (const point &pt) const
    {
        return t>pt.t;
    }
};
int bfs()
{
    priority_queue<point> q;
    memset(vis,0,sizeof(vis));
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            if(grid[i][j]=='S')
            {
                q.push((point){i,j,0});
                vis[i][j]=1;
                break;
            }
    while(!q.empty())
    {
        point pt=q.top();q.pop();
        if(grid[pt.x][pt.y]=='T')return pt.t;

        for(int d=0;d<4;d++)
        {
            int nx=pt.x+dx[d];
            int ny=pt.y+dy[d];
            int nt=pt.t+1;
            if(nx>=1&&nx<=n&&ny>=1&&ny<=m)
            {
                if((grid[nx][ny]=='.'||grid[nx][ny]=='T')&&vis[nx][ny]!=1)
                {
                    q.push( (point) {nx,ny,nt} );
                    vis[nx][ny]=1;
                }
                else if(grid[nx][ny]=='|')
                {
                    if(nt%2==d%2)nt++;
                    int nnx=nx+dx[d],nny=ny+dy[d];
                    if(nnx>=1&&nnx<=n&&nny>=1&&nny<=m&&!vis[nnx][nny])
                    {

                        q.push( (point) {nnx,nny,nt} );
                        vis[nnx][nny]=1;
                    }
                }
                else if(grid[nx][ny]=='-')

                {
                    if(nt%2!=d%2)nt++;
                    int nnx=nx+dx[d],nny=ny+dy[d];
                    if(nnx>=1&&nnx<=n&&nny>=1&&nny<=m&&!vis[nnx][nny])
                    {

                        q.push( (point) {nnx,nny,nt} );
                        vis[nnx][nny]=1;
                    }
                }
            }
        }
    }
    return -1;
}
int main()
{
      while(scanf("%d%d",&n,&m)!=EOF)
    {
        for(int i=1;i<=n;i++)
            scanf("%s",grid[i]+1);
        int num=bfs();
        printf("%d
",num);
    }
    return 0;
}