HDU 1175 ( 连连看 )

讲实话，做得很糟糕，不过这是我广搜的处女题，而且调试了两天才Accept，前面基本上什么错误都出现了，特别是MLE，不会剪枝，做得很吃力，为自己喝彩!
更搞笑的是10000MS的题目，我刚好用了9890MS

Problem : 1175 ( 连连看 )     Judge Status : Accepted
RunId : 5590624    Language : G++    Author : ssun
Code Render Status : Rendered By HDOJ G++ Code Render Version 0.01 Beta

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

const int N = 1005;
int m,n,q;
int map[N][N];
int visit[N][N];
int x1,y1,x2,y2;
int direct[4][2] = {0,-1,1,0,-1,0,0,1};

struct point{
    int x;
    int y;
    int dir;
    int round;
};


bool bfs(int x,int y,int dir, int round)
{
    int i;
    queue<point> pp;
    point now = {x,y,dir,round};
    pp.push(now);
    while(!pp.empty())
    {
        point temp = pp.front();
        pp.pop();        
        if(temp.round > 2) continue;
        for(i=0; i<4; i++)
        {
            now.x = temp.x + direct[i][0];
            now.y = temp.y + direct[i][1];
            if(temp.dir==i || temp.dir == 4 ) now.round = temp.round;
            else now.round = temp.round + 1;
            now.dir = i;                

            if(now.x == x2 && now.y == y2 && now.round<=2) return true;
            if(!map[now.x][now.y] && !visit[now.x][now.y] && now.x >0 && now.y >0 && now.x < n+1 && now.y < m+1)
            {                
                pp.push(now);
            }
        }
        visit[temp.x][temp.y] = 1;
    }
    return false;
}

int main()
{
    int i,j;
    while(cin>>n>>m && (m!=0||n!=0))
    {
        for(i=1; i<=n; i++)
        {
            for(j=1; j<=m; j++)
            {
                cin>>map[i][j];
            }
        }
        cin>>q;
        while(q--)
        {
            memset(visit,0,sizeof(visit));
            cin>>x1>>y1>>x2>>y2;
            if(map[x1][y1] != map[x2][y2])
            {
                cout<<"NO"<<endl;
                continue;
            }
            if(map[x1][y1]!=0 && bfs(x1,y1,4,0))
                cout<<"YES"<<endl;
            else
                cout<<"NO"<<endl;
        }
    }
    return 0;
}

/*
5 5
1 2 3 4 5
0 0 0 0 0 
0 0 0 0 0 
0 0 0 2 2 
5 4 1 2 1 
3
1 5 5 1
1 1 5 5
1 2 5 4


4 4
1 2 3 4
0 0 0 0
0 0 0 0
3 2 1 4
3 
1 1 4 3
1 3 3 1
*/